diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 9509c286236ea..775e4a083996f 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -5397,6 +5397,10 @@ namespace ts {
             return checkTypeAssignableTo(source, target, /*errorNode*/ undefined);
         }
 
+        /**
+         * This is *not* a bi-directional relationship.
+         * If one needs to check both directions for comparability, use a second call to this function or 'checkTypeComparableTo'.
+         */
         function isTypeComparableTo(source: Type, target: Type): boolean {
             return checkTypeComparableTo(source, target, /*errorNode*/ undefined);
         }
@@ -5409,6 +5413,10 @@ namespace ts {
             return checkTypeRelatedTo(source, target, assignableRelation, errorNode, headMessage, containingMessageChain);
         }
 
+        /**
+         * This is *not* a bi-directional relationship.
+         * If one needs to check both directions for comparability, use a second call to this function or 'isTypeComparableTo'.
+         */
         function checkTypeComparableTo(source: Type, target: Type, errorNode: Node, headMessage?: DiagnosticMessage, containingMessageChain?: DiagnosticMessageChain): boolean {
             return checkTypeRelatedTo(source, target, comparableRelation, errorNode, headMessage, containingMessageChain);
         }
@@ -5619,7 +5627,14 @@ namespace ts {
                     sourceType = typeToString(source, /*enclosingDeclaration*/ undefined, TypeFormatFlags.UseFullyQualifiedType);
                     targetType = typeToString(target, /*enclosingDeclaration*/ undefined, TypeFormatFlags.UseFullyQualifiedType);
                 }
-                reportError(message || Diagnostics.Type_0_is_not_assignable_to_type_1, sourceType, targetType);
+
+                if (!message) {
+                    message = relation === comparableRelation ?
+                        Diagnostics.Type_0_is_not_comparable_to_type_1 :
+                        Diagnostics.Type_0_is_not_assignable_to_type_1;
+                }
+
+                reportError(message, sourceType, targetType);
             }
 
             // Compare two types and return
@@ -5648,10 +5663,12 @@ namespace ts {
                     }
                 }
                 if (source.flags & TypeFlags.StringLiteral && target === stringType) return Ternary.True;
+
                 if (relation === assignableRelation || relation === comparableRelation) {
                     if (isTypeAny(source)) return Ternary.True;
                     if (source === numberType && target.flags & TypeFlags.Enum) return Ternary.True;
                 }
+
                 if (source.flags & TypeFlags.Boolean && target.flags & TypeFlags.Boolean) {
                     return Ternary.True;
                 }
@@ -5674,26 +5691,28 @@ namespace ts {
 
                 const saveErrorInfo = errorInfo;
 
-                // Note that the "each" checks must precede the "some" checks to produce the correct results
+                // Note that these checks are specifically ordered to produce correct results.
                 if (source.flags & TypeFlags.Union) {
                     if (relation === comparableRelation) {
-                        if (result = someTypeRelatedToType(<UnionType>source, target, reportErrors)) {
-                            return result;
-                        }
+                        result = someTypeRelatedToType(source as UnionType, target, reportErrors);
                     }
                     else {
-                        if (result = eachTypeRelatedToType(<UnionType>source, target, reportErrors)) {
-                            return result;
-                        }
+                        result = eachTypeRelatedToType(source as UnionType, target, reportErrors);
+                    }
+
+                    if (result) {
+                        return result;
                     }
                 }
                 else if (target.flags & TypeFlags.Intersection) {
-                    if (result = typeRelatedToEachType(source, <IntersectionType>target, reportErrors)) {
+                    result = typeRelatedToEachType(source, target as IntersectionType, reportErrors);
+
+                    if (result) {
                         return result;
                     }
                 }
                 else {
-                    // It is necessary to try "some" checks on both sides because there may be nested "each" checks
+                    // It is necessary to try these "some" checks on both sides because there may be nested "each" checks
                     // on either side that need to be prioritized. For example, A | B = (A | B) & (C | D) or
                     // A & B = (A & B) | (C & D).
                     if (source.flags & TypeFlags.Intersection) {
@@ -5775,8 +5794,8 @@ namespace ts {
                 }
                 if (source.flags & TypeFlags.Union && target.flags & TypeFlags.Union ||
                     source.flags & TypeFlags.Intersection && target.flags & TypeFlags.Intersection) {
-                    if (result = eachTypeRelatedToSomeType(<UnionOrIntersectionType>source, <UnionOrIntersectionType>target)) {
-                        if (result &= eachTypeRelatedToSomeType(<UnionOrIntersectionType>target, <UnionOrIntersectionType>source)) {
+                    if (result = eachTypeRelatedToSomeType(<UnionOrIntersectionType>source, <UnionOrIntersectionType>target, /*reportErrors*/ false)) {
+                        if (result &= eachTypeRelatedToSomeType(<UnionOrIntersectionType>target, <UnionOrIntersectionType>source, /*reportErrors*/ false)) {
                             return result;
                         }
                     }
@@ -5827,7 +5846,7 @@ namespace ts {
                 return false;
             }
 
-            function eachTypeRelatedToSomeType(source: UnionOrIntersectionType, target: UnionOrIntersectionType): Ternary {
+            function eachTypeRelatedToSomeType(source: UnionOrIntersectionType, target: UnionOrIntersectionType, reportErrors: boolean): Ternary {
                 let result = Ternary.True;
                 const sourceTypes = source.types;
                 for (const sourceType of sourceTypes) {
@@ -11015,7 +11034,7 @@ namespace ts {
             if (produceDiagnostics && targetType !== unknownType) {
                 const widenedType = getWidenedType(exprType);
                 if (!isTypeComparableTo(targetType, widenedType)) {
-                    checkTypeComparableTo(exprType, targetType, node, Diagnostics.Neither_type_0_nor_type_1_is_assignable_to_the_other);
+                    checkTypeComparableTo(exprType, targetType, node, Diagnostics.Type_0_cannot_be_converted_to_type_1);
                 }
             }
             return targetType;
@@ -14458,7 +14477,7 @@ namespace ts {
 
                 if (produceDiagnostics && clause.kind === SyntaxKind.CaseClause) {
                     const caseClause = <CaseClause>clause;
-                    // TypeScript 1.0 spec (April 2014):5.9
+                    // TypeScript 1.0 spec (April 2014): 5.9
                     // In a 'switch' statement, each 'case' expression must be of a type that is comparable
                     // to or from the type of the 'switch' expression.
                     const caseType = checkExpression(caseClause.expression);
diff --git a/src/compiler/diagnosticMessages.json b/src/compiler/diagnosticMessages.json
index 585a26da18ccd..39a60f73da091 100644
--- a/src/compiler/diagnosticMessages.json
+++ b/src/compiler/diagnosticMessages.json
@@ -1047,7 +1047,7 @@
         "category": "Error",
         "code": 2351
     },
-    "Neither type '{0}' nor type '{1}' is assignable to the other.": {
+    "Type '{0}' cannot be converted to type '{1}'.": {
         "category": "Error",
         "code": 2352
     },
@@ -1875,6 +1875,10 @@
         "category": "Error",
         "code": 2677
     },
+    "Type '{0}' is not comparable to type '{1}'.": {
+        "category": "Error",
+        "code": 2678
+    },
     "Import declaration '{0}' is using private name '{1}'.": {
         "category": "Error",
         "code": 4000
diff --git a/tests/baselines/reference/arrayCast.errors.txt b/tests/baselines/reference/arrayCast.errors.txt
index 815813ea7276b..61463e5557b4c 100644
--- a/tests/baselines/reference/arrayCast.errors.txt
+++ b/tests/baselines/reference/arrayCast.errors.txt
@@ -1,5 +1,5 @@
-tests/cases/compiler/arrayCast.ts(3,23): error TS2352: Neither type '{ foo: string; }[]' nor type '{ id: number; }[]' is assignable to the other.
-  Type '{ foo: string; }' is not assignable to type '{ id: number; }'.
+tests/cases/compiler/arrayCast.ts(3,23): error TS2352: Type '{ foo: string; }[]' cannot be converted to type '{ id: number; }[]'.
+  Type '{ foo: string; }' is not comparable to type '{ id: number; }'.
     Object literal may only specify known properties, and 'foo' does not exist in type '{ id: number; }'.
 
 
@@ -8,8 +8,8 @@ tests/cases/compiler/arrayCast.ts(3,23): error TS2352: Neither type '{ foo: stri
     // has type { foo: string }[], which is not assignable to { id: number }[].
     <{ id: number; }[]>[{ foo: "s" }];
                           ~~~~~~~~
-!!! error TS2352: Neither type '{ foo: string; }[]' nor type '{ id: number; }[]' is assignable to the other.
-!!! error TS2352:   Type '{ foo: string; }' is not assignable to type '{ id: number; }'.
+!!! error TS2352: Type '{ foo: string; }[]' cannot be converted to type '{ id: number; }[]'.
+!!! error TS2352:   Type '{ foo: string; }' is not comparable to type '{ id: number; }'.
 !!! error TS2352:     Object literal may only specify known properties, and 'foo' does not exist in type '{ id: number; }'.
     
     // Should succeed, as the {} element causes the type of the array to be {}[]
diff --git a/tests/baselines/reference/asOperator2.errors.txt b/tests/baselines/reference/asOperator2.errors.txt
index 3b074038c26b0..92603c25cb021 100644
--- a/tests/baselines/reference/asOperator2.errors.txt
+++ b/tests/baselines/reference/asOperator2.errors.txt
@@ -1,8 +1,8 @@
-tests/cases/conformance/expressions/asOperator/asOperator2.ts(1,9): error TS2352: Neither type 'number' nor type 'string' is assignable to the other.
+tests/cases/conformance/expressions/asOperator/asOperator2.ts(1,9): error TS2352: Type 'number' cannot be converted to type 'string'.
 
 
 ==== tests/cases/conformance/expressions/asOperator/asOperator2.ts (1 errors) ====
     var x = 23 as string;
             ~~~~~~~~~~~~
-!!! error TS2352: Neither type 'number' nor type 'string' is assignable to the other.
+!!! error TS2352: Type 'number' cannot be converted to type 'string'.
     
\ No newline at end of file
diff --git a/tests/baselines/reference/asOperatorContextualType.errors.txt b/tests/baselines/reference/asOperatorContextualType.errors.txt
index c53b407b5cf02..9431d6123e279 100644
--- a/tests/baselines/reference/asOperatorContextualType.errors.txt
+++ b/tests/baselines/reference/asOperatorContextualType.errors.txt
@@ -1,10 +1,10 @@
-tests/cases/conformance/expressions/asOperator/asOperatorContextualType.ts(2,9): error TS2352: Neither type '(v: number) => number' nor type '(x: number) => string' is assignable to the other.
-  Type 'number' is not assignable to type 'string'.
+tests/cases/conformance/expressions/asOperator/asOperatorContextualType.ts(2,9): error TS2352: Type '(v: number) => number' cannot be converted to type '(x: number) => string'.
+  Type 'number' is not comparable to type 'string'.
 
 
 ==== tests/cases/conformance/expressions/asOperator/asOperatorContextualType.ts (1 errors) ====
     // should error
     var x = (v => v) as (x: number) => string;
             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-!!! error TS2352: Neither type '(v: number) => number' nor type '(x: number) => string' is assignable to the other.
-!!! error TS2352:   Type 'number' is not assignable to type 'string'.
\ No newline at end of file
+!!! error TS2352: Type '(v: number) => number' cannot be converted to type '(x: number) => string'.
+!!! error TS2352:   Type 'number' is not comparable to type 'string'.
\ No newline at end of file
diff --git a/tests/baselines/reference/asOperatorNames.errors.txt b/tests/baselines/reference/asOperatorNames.errors.txt
index e3dfaab98845b..4f957791a24d3 100644
--- a/tests/baselines/reference/asOperatorNames.errors.txt
+++ b/tests/baselines/reference/asOperatorNames.errors.txt
@@ -1,11 +1,11 @@
-tests/cases/conformance/expressions/asOperator/asOperatorNames.ts(2,9): error TS2352: Neither type 'number' nor type 'string' is assignable to the other.
+tests/cases/conformance/expressions/asOperator/asOperatorNames.ts(2,9): error TS2352: Type 'number' cannot be converted to type 'string'.
 
 
 ==== tests/cases/conformance/expressions/asOperator/asOperatorNames.ts (1 errors) ====
     var a = 20;
     var b = a as string;
             ~~~~~~~~~~~
-!!! error TS2352: Neither type 'number' nor type 'string' is assignable to the other.
+!!! error TS2352: Type 'number' cannot be converted to type 'string'.
     var as = "hello";
     var as1 = as as string;
     
\ No newline at end of file
diff --git a/tests/baselines/reference/castingTuple.errors.txt b/tests/baselines/reference/castingTuple.errors.txt
index 128ee5b5bb497..6d5549c6bf2ae 100644
--- a/tests/baselines/reference/castingTuple.errors.txt
+++ b/tests/baselines/reference/castingTuple.errors.txt
@@ -1,9 +1,9 @@
-tests/cases/conformance/types/tuple/castingTuple.ts(28,10): error TS2352: Neither type '[number, string]' nor type '[number, number]' is assignable to the other.
+tests/cases/conformance/types/tuple/castingTuple.ts(28,10): error TS2352: Type '[number, string]' cannot be converted to type '[number, number]'.
   Types of property '1' are incompatible.
-    Type 'string' is not assignable to type 'number'.
-tests/cases/conformance/types/tuple/castingTuple.ts(29,10): error TS2352: Neither type '[C, D]' nor type '[A, I]' is assignable to the other.
+    Type 'string' is not comparable to type 'number'.
+tests/cases/conformance/types/tuple/castingTuple.ts(29,10): error TS2352: Type '[C, D]' cannot be converted to type '[A, I]'.
   Types of property '0' are incompatible.
-    Type 'C' is not assignable to type 'A'.
+    Type 'C' is not comparable to type 'A'.
       Property 'a' is missing in type 'C'.
 tests/cases/conformance/types/tuple/castingTuple.ts(30,5): error TS2403: Subsequent variable declarations must have the same type.  Variable 'array1' must be of type '{}[]', but here has type 'number[]'.
 tests/cases/conformance/types/tuple/castingTuple.ts(31,1): error TS2304: Cannot find name 't4'.
@@ -39,14 +39,14 @@ tests/cases/conformance/types/tuple/castingTuple.ts(31,1): error TS2304: Cannot
     // error
     var t3 = <[number, number]>numStrTuple;
              ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-!!! error TS2352: Neither type '[number, string]' nor type '[number, number]' is assignable to the other.
+!!! error TS2352: Type '[number, string]' cannot be converted to type '[number, number]'.
 !!! error TS2352:   Types of property '1' are incompatible.
-!!! error TS2352:     Type 'string' is not assignable to type 'number'.
+!!! error TS2352:     Type 'string' is not comparable to type 'number'.
     var t9 = <[A, I]>classCDTuple;
              ~~~~~~~~~~~~~~~~~~~~
-!!! error TS2352: Neither type '[C, D]' nor type '[A, I]' is assignable to the other.
+!!! error TS2352: Type '[C, D]' cannot be converted to type '[A, I]'.
 !!! error TS2352:   Types of property '0' are incompatible.
-!!! error TS2352:     Type 'C' is not assignable to type 'A'.
+!!! error TS2352:     Type 'C' is not comparable to type 'A'.
 !!! error TS2352:       Property 'a' is missing in type 'C'.
     var array1 = <number[]>numStrTuple;
         ~~~~~~
diff --git a/tests/baselines/reference/contextualTyping39.errors.txt b/tests/baselines/reference/contextualTyping39.errors.txt
index e43624fbead37..9081480f4badf 100644
--- a/tests/baselines/reference/contextualTyping39.errors.txt
+++ b/tests/baselines/reference/contextualTyping39.errors.txt
@@ -1,9 +1,9 @@
-tests/cases/compiler/contextualTyping39.ts(1,11): error TS2352: Neither type '() => string' nor type '() => number' is assignable to the other.
-  Type 'string' is not assignable to type 'number'.
+tests/cases/compiler/contextualTyping39.ts(1,11): error TS2352: Type '() => string' cannot be converted to type '() => number'.
+  Type 'string' is not comparable to type 'number'.
 
 
 ==== tests/cases/compiler/contextualTyping39.ts (1 errors) ====
     var foo = <{ (): number; }> function() { return "err"; };
               ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-!!! error TS2352: Neither type '() => string' nor type '() => number' is assignable to the other.
-!!! error TS2352:   Type 'string' is not assignable to type 'number'.
\ No newline at end of file
+!!! error TS2352: Type '() => string' cannot be converted to type '() => number'.
+!!! error TS2352:   Type 'string' is not comparable to type 'number'.
\ No newline at end of file
diff --git a/tests/baselines/reference/contextualTyping41.errors.txt b/tests/baselines/reference/contextualTyping41.errors.txt
index 1ed6da1b78262..418d435e7fefc 100644
--- a/tests/baselines/reference/contextualTyping41.errors.txt
+++ b/tests/baselines/reference/contextualTyping41.errors.txt
@@ -1,9 +1,9 @@
-tests/cases/compiler/contextualTyping41.ts(1,11): error TS2352: Neither type '() => string' nor type '{ (): number; (i: number): number; }' is assignable to the other.
-  Type 'string' is not assignable to type 'number'.
+tests/cases/compiler/contextualTyping41.ts(1,11): error TS2352: Type '() => string' cannot be converted to type '{ (): number; (i: number): number; }'.
+  Type 'string' is not comparable to type 'number'.
 
 
 ==== tests/cases/compiler/contextualTyping41.ts (1 errors) ====
     var foo = <{():number; (i:number):number; }> (function(){return "err";});
               ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-!!! error TS2352: Neither type '() => string' nor type '{ (): number; (i: number): number; }' is assignable to the other.
-!!! error TS2352:   Type 'string' is not assignable to type 'number'.
\ No newline at end of file
+!!! error TS2352: Type '() => string' cannot be converted to type '{ (): number; (i: number): number; }'.
+!!! error TS2352:   Type 'string' is not comparable to type 'number'.
\ No newline at end of file
diff --git a/tests/baselines/reference/defaultArgsInFunctionExpressions.errors.txt b/tests/baselines/reference/defaultArgsInFunctionExpressions.errors.txt
index 156fdcc4c7a2d..60a9e92bc950e 100644
--- a/tests/baselines/reference/defaultArgsInFunctionExpressions.errors.txt
+++ b/tests/baselines/reference/defaultArgsInFunctionExpressions.errors.txt
@@ -2,9 +2,9 @@ tests/cases/compiler/defaultArgsInFunctionExpressions.ts(4,19): error TS2345: Ar
 tests/cases/compiler/defaultArgsInFunctionExpressions.ts(5,1): error TS2322: Type 'number' is not assignable to type 'string'.
 tests/cases/compiler/defaultArgsInFunctionExpressions.ts(8,20): error TS2322: Type 'number' is not assignable to type 'string'.
 tests/cases/compiler/defaultArgsInFunctionExpressions.ts(11,1): error TS2322: Type 'string' is not assignable to type 'number'.
-tests/cases/compiler/defaultArgsInFunctionExpressions.ts(14,51): error TS2352: Neither type 'string' nor type 'number' is assignable to the other.
+tests/cases/compiler/defaultArgsInFunctionExpressions.ts(14,51): error TS2352: Type 'string' cannot be converted to type 'number'.
 tests/cases/compiler/defaultArgsInFunctionExpressions.ts(17,41): error TS2322: Type 'string' is not assignable to type 'number'.
-tests/cases/compiler/defaultArgsInFunctionExpressions.ts(20,62): error TS2352: Neither type 'string' nor type 'number' is assignable to the other.
+tests/cases/compiler/defaultArgsInFunctionExpressions.ts(20,62): error TS2352: Type 'string' cannot be converted to type 'number'.
 tests/cases/compiler/defaultArgsInFunctionExpressions.ts(28,15): error TS2304: Cannot find name 'T'.
 
 
@@ -32,7 +32,7 @@ tests/cases/compiler/defaultArgsInFunctionExpressions.ts(28,15): error TS2304: C
     // Contextually type the default arg with the type annotation
     var f3 = function (a: (s: string) => any = (s) => <number>s) { };
                                                       ~~~~~~~~~
-!!! error TS2352: Neither type 'string' nor type 'number' is assignable to the other.
+!!! error TS2352: Type 'string' cannot be converted to type 'number'.
     
     // Type check using the function's contextual type
     var f4: (a: number) => void = function (a = "") { };
@@ -42,7 +42,7 @@ tests/cases/compiler/defaultArgsInFunctionExpressions.ts(28,15): error TS2304: C
     // Contextually type the default arg using the function's contextual type
     var f5: (a: (s: string) => any) => void = function (a = s => <number>s) { };
                                                                  ~~~~~~~~~
-!!! error TS2352: Neither type 'string' nor type 'number' is assignable to the other.
+!!! error TS2352: Type 'string' cannot be converted to type 'number'.
     
     // Instantiated module
     module T { }
diff --git a/tests/baselines/reference/equalityWithIntersectionTypes01.errors.txt b/tests/baselines/reference/equalityWithIntersectionTypes01.errors.txt
new file mode 100644
index 0000000000000..8bffff2218b5c
--- /dev/null
+++ b/tests/baselines/reference/equalityWithIntersectionTypes01.errors.txt
@@ -0,0 +1,51 @@
+tests/cases/conformance/types/typeRelationships/comparable/equalityWithIntersectionTypes01.ts(17,5): error TS2365: Operator '===' cannot be applied to types 'I1 & I3' and 'I2'.
+tests/cases/conformance/types/typeRelationships/comparable/equalityWithIntersectionTypes01.ts(17,16): error TS2365: Operator '===' cannot be applied to types 'I2' and 'I1 & I3'.
+tests/cases/conformance/types/typeRelationships/comparable/equalityWithIntersectionTypes01.ts(19,10): error TS2365: Operator '!==' cannot be applied to types 'I1 & I3' and 'I2'.
+tests/cases/conformance/types/typeRelationships/comparable/equalityWithIntersectionTypes01.ts(19,21): error TS2365: Operator '!==' cannot be applied to types 'I2' and 'I1 & I3'.
+tests/cases/conformance/types/typeRelationships/comparable/equalityWithIntersectionTypes01.ts(21,10): error TS2365: Operator '==' cannot be applied to types 'I1 & I3' and 'I2'.
+tests/cases/conformance/types/typeRelationships/comparable/equalityWithIntersectionTypes01.ts(21,20): error TS2365: Operator '==' cannot be applied to types 'I2' and 'I1 & I3'.
+tests/cases/conformance/types/typeRelationships/comparable/equalityWithIntersectionTypes01.ts(23,10): error TS2365: Operator '!=' cannot be applied to types 'I1 & I3' and 'I2'.
+tests/cases/conformance/types/typeRelationships/comparable/equalityWithIntersectionTypes01.ts(23,20): error TS2365: Operator '!=' cannot be applied to types 'I2' and 'I1 & I3'.
+
+
+==== tests/cases/conformance/types/typeRelationships/comparable/equalityWithIntersectionTypes01.ts (8 errors) ====
+    interface I1 {
+        p1: number
+    }
+    
+    interface I2 extends I1 {
+        p2: number;
+    }
+    
+    interface I3 {
+        p3: number;
+    }
+    
+    var x = { p1: 10, p2: 20, p3: 30 };
+    var y: I1 & I3 = x;
+    var z: I2 = x;
+    
+    if (y === z || z === y) {
+        ~~~~~~~
+!!! error TS2365: Operator '===' cannot be applied to types 'I1 & I3' and 'I2'.
+                   ~~~~~~~
+!!! error TS2365: Operator '===' cannot be applied to types 'I2' and 'I1 & I3'.
+    }
+    else if (y !== z || z !== y) {
+             ~~~~~~~
+!!! error TS2365: Operator '!==' cannot be applied to types 'I1 & I3' and 'I2'.
+                        ~~~~~~~
+!!! error TS2365: Operator '!==' cannot be applied to types 'I2' and 'I1 & I3'.
+    }
+    else if (y == z || z == y) {
+             ~~~~~~
+!!! error TS2365: Operator '==' cannot be applied to types 'I1 & I3' and 'I2'.
+                       ~~~~~~
+!!! error TS2365: Operator '==' cannot be applied to types 'I2' and 'I1 & I3'.
+    }
+    else if (y != z || z != y) {
+             ~~~~~~
+!!! error TS2365: Operator '!=' cannot be applied to types 'I1 & I3' and 'I2'.
+                       ~~~~~~
+!!! error TS2365: Operator '!=' cannot be applied to types 'I2' and 'I1 & I3'.
+    }
\ No newline at end of file
diff --git a/tests/baselines/reference/equalityWithIntersectionTypes01.js b/tests/baselines/reference/equalityWithIntersectionTypes01.js
new file mode 100644
index 0000000000000..151809bb6f8a5
--- /dev/null
+++ b/tests/baselines/reference/equalityWithIntersectionTypes01.js
@@ -0,0 +1,38 @@
+//// [equalityWithIntersectionTypes01.ts]
+interface I1 {
+    p1: number
+}
+
+interface I2 extends I1 {
+    p2: number;
+}
+
+interface I3 {
+    p3: number;
+}
+
+var x = { p1: 10, p2: 20, p3: 30 };
+var y: I1 & I3 = x;
+var z: I2 = x;
+
+if (y === z || z === y) {
+}
+else if (y !== z || z !== y) {
+}
+else if (y == z || z == y) {
+}
+else if (y != z || z != y) {
+}
+
+//// [equalityWithIntersectionTypes01.js]
+var x = { p1: 10, p2: 20, p3: 30 };
+var y = x;
+var z = x;
+if (y === z || z === y) {
+}
+else if (y !== z || z !== y) {
+}
+else if (y == z || z == y) {
+}
+else if (y != z || z != y) {
+}
diff --git a/tests/baselines/reference/equalityWithUnionTypes01.js b/tests/baselines/reference/equalityWithUnionTypes01.js
new file mode 100644
index 0000000000000..05e9f25cd69ac
--- /dev/null
+++ b/tests/baselines/reference/equalityWithUnionTypes01.js
@@ -0,0 +1,34 @@
+//// [equalityWithUnionTypes01.ts]
+interface I1 {
+    p1: number
+}
+
+interface I2 extends I1 {
+    p2: number;
+}
+
+var x = { p1: 10, p2: 20 };
+var y: number | I2 = x;
+var z: I1 = x;
+
+if (y === z || z === y) {
+}
+else if (y !== z || z !== y) {
+}
+else if (y == z || z == y) {
+}
+else if (y != z || z != y) {
+}
+
+//// [equalityWithUnionTypes01.js]
+var x = { p1: 10, p2: 20 };
+var y = x;
+var z = x;
+if (y === z || z === y) {
+}
+else if (y !== z || z !== y) {
+}
+else if (y == z || z == y) {
+}
+else if (y != z || z != y) {
+}
diff --git a/tests/baselines/reference/equalityWithUnionTypes01.symbols b/tests/baselines/reference/equalityWithUnionTypes01.symbols
new file mode 100644
index 0000000000000..0b1a689251739
--- /dev/null
+++ b/tests/baselines/reference/equalityWithUnionTypes01.symbols
@@ -0,0 +1,55 @@
+=== tests/cases/conformance/types/typeRelationships/comparable/equalityWithUnionTypes01.ts ===
+interface I1 {
+>I1 : Symbol(I1, Decl(equalityWithUnionTypes01.ts, 0, 0))
+
+    p1: number
+>p1 : Symbol(I1.p1, Decl(equalityWithUnionTypes01.ts, 0, 14))
+}
+
+interface I2 extends I1 {
+>I2 : Symbol(I2, Decl(equalityWithUnionTypes01.ts, 2, 1))
+>I1 : Symbol(I1, Decl(equalityWithUnionTypes01.ts, 0, 0))
+
+    p2: number;
+>p2 : Symbol(I2.p2, Decl(equalityWithUnionTypes01.ts, 4, 25))
+}
+
+var x = { p1: 10, p2: 20 };
+>x : Symbol(x, Decl(equalityWithUnionTypes01.ts, 8, 3))
+>p1 : Symbol(p1, Decl(equalityWithUnionTypes01.ts, 8, 9))
+>p2 : Symbol(p2, Decl(equalityWithUnionTypes01.ts, 8, 17))
+
+var y: number | I2 = x;
+>y : Symbol(y, Decl(equalityWithUnionTypes01.ts, 9, 3))
+>I2 : Symbol(I2, Decl(equalityWithUnionTypes01.ts, 2, 1))
+>x : Symbol(x, Decl(equalityWithUnionTypes01.ts, 8, 3))
+
+var z: I1 = x;
+>z : Symbol(z, Decl(equalityWithUnionTypes01.ts, 10, 3))
+>I1 : Symbol(I1, Decl(equalityWithUnionTypes01.ts, 0, 0))
+>x : Symbol(x, Decl(equalityWithUnionTypes01.ts, 8, 3))
+
+if (y === z || z === y) {
+>y : Symbol(y, Decl(equalityWithUnionTypes01.ts, 9, 3))
+>z : Symbol(z, Decl(equalityWithUnionTypes01.ts, 10, 3))
+>z : Symbol(z, Decl(equalityWithUnionTypes01.ts, 10, 3))
+>y : Symbol(y, Decl(equalityWithUnionTypes01.ts, 9, 3))
+}
+else if (y !== z || z !== y) {
+>y : Symbol(y, Decl(equalityWithUnionTypes01.ts, 9, 3))
+>z : Symbol(z, Decl(equalityWithUnionTypes01.ts, 10, 3))
+>z : Symbol(z, Decl(equalityWithUnionTypes01.ts, 10, 3))
+>y : Symbol(y, Decl(equalityWithUnionTypes01.ts, 9, 3))
+}
+else if (y == z || z == y) {
+>y : Symbol(y, Decl(equalityWithUnionTypes01.ts, 9, 3))
+>z : Symbol(z, Decl(equalityWithUnionTypes01.ts, 10, 3))
+>z : Symbol(z, Decl(equalityWithUnionTypes01.ts, 10, 3))
+>y : Symbol(y, Decl(equalityWithUnionTypes01.ts, 9, 3))
+}
+else if (y != z || z != y) {
+>y : Symbol(y, Decl(equalityWithUnionTypes01.ts, 9, 3))
+>z : Symbol(z, Decl(equalityWithUnionTypes01.ts, 10, 3))
+>z : Symbol(z, Decl(equalityWithUnionTypes01.ts, 10, 3))
+>y : Symbol(y, Decl(equalityWithUnionTypes01.ts, 9, 3))
+}
diff --git a/tests/baselines/reference/equalityWithUnionTypes01.types b/tests/baselines/reference/equalityWithUnionTypes01.types
new file mode 100644
index 0000000000000..27bf01c048bf4
--- /dev/null
+++ b/tests/baselines/reference/equalityWithUnionTypes01.types
@@ -0,0 +1,70 @@
+=== tests/cases/conformance/types/typeRelationships/comparable/equalityWithUnionTypes01.ts ===
+interface I1 {
+>I1 : I1
+
+    p1: number
+>p1 : number
+}
+
+interface I2 extends I1 {
+>I2 : I2
+>I1 : I1
+
+    p2: number;
+>p2 : number
+}
+
+var x = { p1: 10, p2: 20 };
+>x : { p1: number; p2: number; }
+>{ p1: 10, p2: 20 } : { p1: number; p2: number; }
+>p1 : number
+>10 : number
+>p2 : number
+>20 : number
+
+var y: number | I2 = x;
+>y : number | I2
+>I2 : I2
+>x : { p1: number; p2: number; }
+
+var z: I1 = x;
+>z : I1
+>I1 : I1
+>x : { p1: number; p2: number; }
+
+if (y === z || z === y) {
+>y === z || z === y : boolean
+>y === z : boolean
+>y : number | I2
+>z : I1
+>z === y : boolean
+>z : I1
+>y : number | I2
+}
+else if (y !== z || z !== y) {
+>y !== z || z !== y : boolean
+>y !== z : boolean
+>y : number | I2
+>z : I1
+>z !== y : boolean
+>z : I1
+>y : number | I2
+}
+else if (y == z || z == y) {
+>y == z || z == y : boolean
+>y == z : boolean
+>y : number | I2
+>z : I1
+>z == y : boolean
+>z : I1
+>y : number | I2
+}
+else if (y != z || z != y) {
+>y != z || z != y : boolean
+>y != z : boolean
+>y : number | I2
+>z : I1
+>z != y : boolean
+>z : I1
+>y : number | I2
+}
diff --git a/tests/baselines/reference/fuzzy.errors.txt b/tests/baselines/reference/fuzzy.errors.txt
index 0aa8207ff9879..344a3865fb2a5 100644
--- a/tests/baselines/reference/fuzzy.errors.txt
+++ b/tests/baselines/reference/fuzzy.errors.txt
@@ -5,7 +5,7 @@ tests/cases/compiler/fuzzy.ts(21,20): error TS2322: Type '{ anything: number; on
     Type 'this' is not assignable to type 'I'.
       Type 'C' is not assignable to type 'I'.
         Property 'alsoWorks' is missing in type 'C'.
-tests/cases/compiler/fuzzy.ts(25,20): error TS2352: Neither type '{ oneI: this; }' nor type 'R' is assignable to the other.
+tests/cases/compiler/fuzzy.ts(25,20): error TS2352: Type '{ oneI: this; }' cannot be converted to type 'R'.
   Property 'anything' is missing in type '{ oneI: this; }'.
 
 
@@ -45,7 +45,7 @@ tests/cases/compiler/fuzzy.ts(25,20): error TS2352: Neither type '{ oneI: this;
             worksToo():R {
                 return <R>({ oneI: this });
                        ~~~~~~~~~~~~~~~~~~~
-!!! error TS2352: Neither type '{ oneI: this; }' nor type 'R' is assignable to the other.
+!!! error TS2352: Type '{ oneI: this; }' cannot be converted to type 'R'.
 !!! error TS2352:   Property 'anything' is missing in type '{ oneI: this; }'.
             }
         }
diff --git a/tests/baselines/reference/genericTypeAssertions1.errors.txt b/tests/baselines/reference/genericTypeAssertions1.errors.txt
index 5479c5f948eae..aa5f14f5da858 100644
--- a/tests/baselines/reference/genericTypeAssertions1.errors.txt
+++ b/tests/baselines/reference/genericTypeAssertions1.errors.txt
@@ -2,8 +2,8 @@ tests/cases/compiler/genericTypeAssertions1.ts(3,5): error TS2322: Type 'A<numbe
   Type 'number' is not assignable to type 'string'.
 tests/cases/compiler/genericTypeAssertions1.ts(4,5): error TS2322: Type 'A<A<number>>' is not assignable to type 'A<number>'.
   Type 'A<number>' is not assignable to type 'number'.
-tests/cases/compiler/genericTypeAssertions1.ts(4,21): error TS2352: Neither type 'A<number>' nor type 'A<A<number>>' is assignable to the other.
-  Type 'number' is not assignable to type 'A<number>'.
+tests/cases/compiler/genericTypeAssertions1.ts(4,21): error TS2352: Type 'A<number>' cannot be converted to type 'A<A<number>>'.
+  Type 'number' is not comparable to type 'A<number>'.
 
 
 ==== tests/cases/compiler/genericTypeAssertions1.ts (3 errors) ====
@@ -18,5 +18,5 @@ tests/cases/compiler/genericTypeAssertions1.ts(4,21): error TS2352: Neither type
 !!! error TS2322: Type 'A<A<number>>' is not assignable to type 'A<number>'.
 !!! error TS2322:   Type 'A<number>' is not assignable to type 'number'.
                         ~~~~~~~~~~~~~~~~~
-!!! error TS2352: Neither type 'A<number>' nor type 'A<A<number>>' is assignable to the other.
-!!! error TS2352:   Type 'number' is not assignable to type 'A<number>'.
\ No newline at end of file
+!!! error TS2352: Type 'A<number>' cannot be converted to type 'A<A<number>>'.
+!!! error TS2352:   Type 'number' is not comparable to type 'A<number>'.
\ No newline at end of file
diff --git a/tests/baselines/reference/genericTypeAssertions2.errors.txt b/tests/baselines/reference/genericTypeAssertions2.errors.txt
index e424e6a13b101..756690f178378 100644
--- a/tests/baselines/reference/genericTypeAssertions2.errors.txt
+++ b/tests/baselines/reference/genericTypeAssertions2.errors.txt
@@ -5,7 +5,7 @@ tests/cases/compiler/genericTypeAssertions2.ts(10,5): error TS2322: Type 'B<stri
         Type 'number' is not assignable to type 'string'.
 tests/cases/compiler/genericTypeAssertions2.ts(11,5): error TS2322: Type 'A<number>' is not assignable to type 'B<number>'.
   Property 'bar' is missing in type 'A<number>'.
-tests/cases/compiler/genericTypeAssertions2.ts(13,21): error TS2352: Neither type 'undefined[]' nor type 'A<number>' is assignable to the other.
+tests/cases/compiler/genericTypeAssertions2.ts(13,21): error TS2352: Type 'undefined[]' cannot be converted to type 'A<number>'.
   Property 'foo' is missing in type 'undefined[]'.
 
 
@@ -33,5 +33,5 @@ tests/cases/compiler/genericTypeAssertions2.ts(13,21): error TS2352: Neither typ
     var r4: A<number> = <A<number>>new A();
     var r5: A<number> = <A<number>>[]; // error
                         ~~~~~~~~~~~~~
-!!! error TS2352: Neither type 'undefined[]' nor type 'A<number>' is assignable to the other.
+!!! error TS2352: Type 'undefined[]' cannot be converted to type 'A<number>'.
 !!! error TS2352:   Property 'foo' is missing in type 'undefined[]'.
\ No newline at end of file
diff --git a/tests/baselines/reference/genericTypeAssertions4.errors.txt b/tests/baselines/reference/genericTypeAssertions4.errors.txt
index 055de774b3921..401834930f30f 100644
--- a/tests/baselines/reference/genericTypeAssertions4.errors.txt
+++ b/tests/baselines/reference/genericTypeAssertions4.errors.txt
@@ -1,8 +1,8 @@
 tests/cases/compiler/genericTypeAssertions4.ts(19,5): error TS2322: Type 'A' is not assignable to type 'T'.
 tests/cases/compiler/genericTypeAssertions4.ts(20,5): error TS2322: Type 'B' is not assignable to type 'T'.
 tests/cases/compiler/genericTypeAssertions4.ts(21,5): error TS2322: Type 'C' is not assignable to type 'T'.
-tests/cases/compiler/genericTypeAssertions4.ts(23,9): error TS2352: Neither type 'B' nor type 'T' is assignable to the other.
-tests/cases/compiler/genericTypeAssertions4.ts(24,9): error TS2352: Neither type 'C' nor type 'T' is assignable to the other.
+tests/cases/compiler/genericTypeAssertions4.ts(23,9): error TS2352: Type 'B' cannot be converted to type 'T'.
+tests/cases/compiler/genericTypeAssertions4.ts(24,9): error TS2352: Type 'C' cannot be converted to type 'T'.
 
 
 ==== tests/cases/compiler/genericTypeAssertions4.ts (5 errors) ====
@@ -36,8 +36,8 @@ tests/cases/compiler/genericTypeAssertions4.ts(24,9): error TS2352: Neither type
         y = <T>a;
         y = <T>b; // error: cannot convert B to T
             ~~~~
-!!! error TS2352: Neither type 'B' nor type 'T' is assignable to the other.
+!!! error TS2352: Type 'B' cannot be converted to type 'T'.
         y = <T>c; // error: cannot convert C to T
             ~~~~
-!!! error TS2352: Neither type 'C' nor type 'T' is assignable to the other.
+!!! error TS2352: Type 'C' cannot be converted to type 'T'.
     }
\ No newline at end of file
diff --git a/tests/baselines/reference/genericTypeAssertions5.errors.txt b/tests/baselines/reference/genericTypeAssertions5.errors.txt
index e315a7f122ab9..45f7607336385 100644
--- a/tests/baselines/reference/genericTypeAssertions5.errors.txt
+++ b/tests/baselines/reference/genericTypeAssertions5.errors.txt
@@ -1,8 +1,8 @@
 tests/cases/compiler/genericTypeAssertions5.ts(19,5): error TS2322: Type 'A' is not assignable to type 'T'.
 tests/cases/compiler/genericTypeAssertions5.ts(20,5): error TS2322: Type 'B' is not assignable to type 'T'.
 tests/cases/compiler/genericTypeAssertions5.ts(21,5): error TS2322: Type 'C' is not assignable to type 'T'.
-tests/cases/compiler/genericTypeAssertions5.ts(23,9): error TS2352: Neither type 'B' nor type 'T' is assignable to the other.
-tests/cases/compiler/genericTypeAssertions5.ts(24,9): error TS2352: Neither type 'C' nor type 'T' is assignable to the other.
+tests/cases/compiler/genericTypeAssertions5.ts(23,9): error TS2352: Type 'B' cannot be converted to type 'T'.
+tests/cases/compiler/genericTypeAssertions5.ts(24,9): error TS2352: Type 'C' cannot be converted to type 'T'.
 
 
 ==== tests/cases/compiler/genericTypeAssertions5.ts (5 errors) ====
@@ -36,8 +36,8 @@ tests/cases/compiler/genericTypeAssertions5.ts(24,9): error TS2352: Neither type
         y = <T>a;
         y = <T>b; // error: cannot convert B to T
             ~~~~
-!!! error TS2352: Neither type 'B' nor type 'T' is assignable to the other.
+!!! error TS2352: Type 'B' cannot be converted to type 'T'.
         y = <T>c; // error: cannot convert C to T
             ~~~~
-!!! error TS2352: Neither type 'C' nor type 'T' is assignable to the other.
+!!! error TS2352: Type 'C' cannot be converted to type 'T'.
     }
\ No newline at end of file
diff --git a/tests/baselines/reference/genericTypeAssertions6.errors.txt b/tests/baselines/reference/genericTypeAssertions6.errors.txt
index 29ca99ecb1adc..1bda683b88a23 100644
--- a/tests/baselines/reference/genericTypeAssertions6.errors.txt
+++ b/tests/baselines/reference/genericTypeAssertions6.errors.txt
@@ -1,7 +1,7 @@
-tests/cases/compiler/genericTypeAssertions6.ts(8,13): error TS2352: Neither type 'U' nor type 'T' is assignable to the other.
-tests/cases/compiler/genericTypeAssertions6.ts(9,13): error TS2352: Neither type 'T' nor type 'U' is assignable to the other.
-tests/cases/compiler/genericTypeAssertions6.ts(19,17): error TS2352: Neither type 'U' nor type 'T' is assignable to the other.
-  Type 'Date' is not assignable to type 'T'.
+tests/cases/compiler/genericTypeAssertions6.ts(8,13): error TS2352: Type 'U' cannot be converted to type 'T'.
+tests/cases/compiler/genericTypeAssertions6.ts(9,13): error TS2352: Type 'T' cannot be converted to type 'U'.
+tests/cases/compiler/genericTypeAssertions6.ts(19,17): error TS2352: Type 'U' cannot be converted to type 'T'.
+  Type 'Date' is not comparable to type 'T'.
 
 
 ==== tests/cases/compiler/genericTypeAssertions6.ts (3 errors) ====
@@ -14,10 +14,10 @@ tests/cases/compiler/genericTypeAssertions6.ts(19,17): error TS2352: Neither typ
         f(x: T, y: U) {
             x = <T>y;
                 ~~~~
-!!! error TS2352: Neither type 'U' nor type 'T' is assignable to the other.
+!!! error TS2352: Type 'U' cannot be converted to type 'T'.
             y = <U>x;
                 ~~~~
-!!! error TS2352: Neither type 'T' nor type 'U' is assignable to the other.
+!!! error TS2352: Type 'T' cannot be converted to type 'U'.
         }
     }
     
@@ -29,8 +29,8 @@ tests/cases/compiler/genericTypeAssertions6.ts(19,17): error TS2352: Neither typ
             var d = <U>new Date();
             var e = <T><U>new Date();
                     ~~~~~~~~~~~~~~~~
-!!! error TS2352: Neither type 'U' nor type 'T' is assignable to the other.
-!!! error TS2352:   Type 'Date' is not assignable to type 'T'.
+!!! error TS2352: Type 'U' cannot be converted to type 'T'.
+!!! error TS2352:   Type 'Date' is not comparable to type 'T'.
         }
     }
     
diff --git a/tests/baselines/reference/intTypeCheck.errors.txt b/tests/baselines/reference/intTypeCheck.errors.txt
index a860f5e360495..0d19c6b2b6e61 100644
--- a/tests/baselines/reference/intTypeCheck.errors.txt
+++ b/tests/baselines/reference/intTypeCheck.errors.txt
@@ -70,7 +70,7 @@ tests/cases/compiler/intTypeCheck.ts(182,5): error TS2322: Type '{}' is not assi
   Type '{}' provides no match for the signature 'new (): any'
 tests/cases/compiler/intTypeCheck.ts(183,5): error TS2322: Type 'Object' is not assignable to type 'i7'.
   Type 'Object' provides no match for the signature 'new (): any'
-tests/cases/compiler/intTypeCheck.ts(185,17): error TS2352: Neither type 'Base' nor type 'i7' is assignable to the other.
+tests/cases/compiler/intTypeCheck.ts(185,17): error TS2352: Type 'Base' cannot be converted to type 'i7'.
   Type 'Base' provides no match for the signature 'new (): any'
 tests/cases/compiler/intTypeCheck.ts(187,5): error TS2322: Type '() => void' is not assignable to type 'i7'.
   Type '() => void' provides no match for the signature 'new (): any'
@@ -396,7 +396,7 @@ tests/cases/compiler/intTypeCheck.ts(205,17): error TS2351: Cannot use 'new' wit
     var obj69: i7 = new obj66;
     var obj70: i7 = <i7>new Base;
                     ~~~~~~~~~~~~
-!!! error TS2352: Neither type 'Base' nor type 'i7' is assignable to the other.
+!!! error TS2352: Type 'Base' cannot be converted to type 'i7'.
 !!! error TS2352:   Type 'Base' provides no match for the signature 'new (): any'
     var obj71: i7 = null;
     var obj72: i7 = function () { };
diff --git a/tests/baselines/reference/literals-negative.errors.txt b/tests/baselines/reference/literals-negative.errors.txt
index d783e5dfa0212..2024066d9f264 100644
--- a/tests/baselines/reference/literals-negative.errors.txt
+++ b/tests/baselines/reference/literals-negative.errors.txt
@@ -1,4 +1,4 @@
-tests/cases/compiler/literals-negative.ts(5,9): error TS2352: Neither type 'number' nor type 'boolean' is assignable to the other.
+tests/cases/compiler/literals-negative.ts(5,9): error TS2352: Type 'number' cannot be converted to type 'boolean'.
 
 
 ==== tests/cases/compiler/literals-negative.ts (1 errors) ====
@@ -8,7 +8,7 @@ tests/cases/compiler/literals-negative.ts(5,9): error TS2352: Neither type 'numb
     var s = <string>(null);
     var b = <boolean>(n);
             ~~~~~~~~~~~~
-!!! error TS2352: Neither type 'number' nor type 'boolean' is assignable to the other.
+!!! error TS2352: Type 'number' cannot be converted to type 'boolean'.
     
     function isVoid() : void { }
     
diff --git a/tests/baselines/reference/noImplicitAnyInCastExpression.errors.txt b/tests/baselines/reference/noImplicitAnyInCastExpression.errors.txt
index 66a7773ab4993..8243a9c68ce8d 100644
--- a/tests/baselines/reference/noImplicitAnyInCastExpression.errors.txt
+++ b/tests/baselines/reference/noImplicitAnyInCastExpression.errors.txt
@@ -1,4 +1,4 @@
-tests/cases/compiler/noImplicitAnyInCastExpression.ts(16,2): error TS2352: Neither type '{ c: null; }' nor type 'IFoo' is assignable to the other.
+tests/cases/compiler/noImplicitAnyInCastExpression.ts(16,2): error TS2352: Type '{ c: null; }' cannot be converted to type 'IFoo'.
   Property 'a' is missing in type '{ c: null; }'.
 
 
@@ -20,5 +20,5 @@ tests/cases/compiler/noImplicitAnyInCastExpression.ts(16,2): error TS2352: Neith
     // Neither types is assignable to each other
     (<IFoo>{ c: null });
      ~~~~~~~~~~~~~~~~~
-!!! error TS2352: Neither type '{ c: null; }' nor type 'IFoo' is assignable to the other.
+!!! error TS2352: Type '{ c: null; }' cannot be converted to type 'IFoo'.
 !!! error TS2352:   Property 'a' is missing in type '{ c: null; }'.
\ No newline at end of file
diff --git a/tests/baselines/reference/objectTypesIdentityWithPrivates3.errors.txt b/tests/baselines/reference/objectTypesIdentityWithPrivates3.errors.txt
index 9cbaa7300221d..2342065605be9 100644
--- a/tests/baselines/reference/objectTypesIdentityWithPrivates3.errors.txt
+++ b/tests/baselines/reference/objectTypesIdentityWithPrivates3.errors.txt
@@ -1,4 +1,4 @@
-tests/cases/conformance/types/typeRelationships/typeAndMemberIdentity/objectTypesIdentityWithPrivates3.ts(25,1): error TS2352: Neither type 'C3<T2>' nor type 'C4' is assignable to the other.
+tests/cases/conformance/types/typeRelationships/typeAndMemberIdentity/objectTypesIdentityWithPrivates3.ts(25,1): error TS2352: Type 'C3<T2>' cannot be converted to type 'C4'.
   Property 'y' is missing in type 'C3<T2>'.
 
 
@@ -29,5 +29,5 @@ tests/cases/conformance/types/typeRelationships/typeAndMemberIdentity/objectType
     var c3: C3<T2>;
     <C4>c3; // Should fail (private x originates in the same declaration, but different types)
     ~~~~~~
-!!! error TS2352: Neither type 'C3<T2>' nor type 'C4' is assignable to the other.
+!!! error TS2352: Type 'C3<T2>' cannot be converted to type 'C4'.
 !!! error TS2352:   Property 'y' is missing in type 'C3<T2>'.
\ No newline at end of file
diff --git a/tests/baselines/reference/switchAssignmentCompat.errors.txt b/tests/baselines/reference/switchAssignmentCompat.errors.txt
index 6a2755365ab21..747a1035b6846 100644
--- a/tests/baselines/reference/switchAssignmentCompat.errors.txt
+++ b/tests/baselines/reference/switchAssignmentCompat.errors.txt
@@ -1,4 +1,4 @@
-tests/cases/compiler/switchAssignmentCompat.ts(4,10): error TS2322: Type 'typeof Foo' is not assignable to type 'number'.
+tests/cases/compiler/switchAssignmentCompat.ts(4,10): error TS2678: Type 'typeof Foo' is not comparable to type 'number'.
 
 
 ==== tests/cases/compiler/switchAssignmentCompat.ts (1 errors) ====
@@ -7,6 +7,6 @@ tests/cases/compiler/switchAssignmentCompat.ts(4,10): error TS2322: Type 'typeof
     switch (0) {
         case Foo: break; // Error expected
              ~~~
-!!! error TS2322: Type 'typeof Foo' is not assignable to type 'number'.
+!!! error TS2678: Type 'typeof Foo' is not comparable to type 'number'.
     }
     
\ No newline at end of file
diff --git a/tests/baselines/reference/switchCaseWithIntersectionTypes01.errors.txt b/tests/baselines/reference/switchCaseWithIntersectionTypes01.errors.txt
new file mode 100644
index 0000000000000..d42f407a784d9
--- /dev/null
+++ b/tests/baselines/reference/switchCaseWithIntersectionTypes01.errors.txt
@@ -0,0 +1,38 @@
+tests/cases/conformance/types/typeRelationships/comparable/switchCaseWithIntersectionTypes01.ts(19,10): error TS2678: Type 'number & boolean' is not comparable to type 'string & number'.
+  Type 'number & boolean' is not comparable to type 'string'.
+tests/cases/conformance/types/typeRelationships/comparable/switchCaseWithIntersectionTypes01.ts(23,10): error TS2678: Type 'boolean' is not comparable to type 'string & number'.
+  Type 'boolean' is not comparable to type 'string'.
+
+
+==== tests/cases/conformance/types/typeRelationships/comparable/switchCaseWithIntersectionTypes01.ts (2 errors) ====
+    
+    var strAndNum: string & number;
+    var numAndBool: number & boolean;
+    var str: string;
+    var num: number;
+    var bool: boolean;
+    
+    switch (strAndNum) {
+        // Identical
+        case strAndNum:
+            break;
+    
+        // Constituents
+        case str:
+        case num:
+            break;
+    
+        // Overlap in constituents
+        case numAndBool:
+             ~~~~~~~~~~
+!!! error TS2678: Type 'number & boolean' is not comparable to type 'string & number'.
+!!! error TS2678:   Type 'number & boolean' is not comparable to type 'string'.
+            break;
+    
+        // No relation
+        case bool:
+             ~~~~
+!!! error TS2678: Type 'boolean' is not comparable to type 'string & number'.
+!!! error TS2678:   Type 'boolean' is not comparable to type 'string'.
+            break;
+    }
\ No newline at end of file
diff --git a/tests/baselines/reference/switchCaseWithIntersectionTypes01.js b/tests/baselines/reference/switchCaseWithIntersectionTypes01.js
new file mode 100644
index 0000000000000..4e0ddf7ea76a9
--- /dev/null
+++ b/tests/baselines/reference/switchCaseWithIntersectionTypes01.js
@@ -0,0 +1,48 @@
+//// [switchCaseWithIntersectionTypes01.ts]
+
+var strAndNum: string & number;
+var numAndBool: number & boolean;
+var str: string;
+var num: number;
+var bool: boolean;
+
+switch (strAndNum) {
+    // Identical
+    case strAndNum:
+        break;
+
+    // Constituents
+    case str:
+    case num:
+        break;
+
+    // Overlap in constituents
+    case numAndBool:
+        break;
+
+    // No relation
+    case bool:
+        break;
+}
+
+//// [switchCaseWithIntersectionTypes01.js]
+var strAndNum;
+var numAndBool;
+var str;
+var num;
+var bool;
+switch (strAndNum) {
+    // Identical
+    case strAndNum:
+        break;
+    // Constituents
+    case str:
+    case num:
+        break;
+    // Overlap in constituents
+    case numAndBool:
+        break;
+    // No relation
+    case bool:
+        break;
+}
diff --git a/tests/baselines/reference/switchCaseWithUnionTypes01.errors.txt b/tests/baselines/reference/switchCaseWithUnionTypes01.errors.txt
new file mode 100644
index 0000000000000..5f164f5734375
--- /dev/null
+++ b/tests/baselines/reference/switchCaseWithUnionTypes01.errors.txt
@@ -0,0 +1,31 @@
+tests/cases/conformance/types/typeRelationships/comparable/switchCaseWithUnionTypes01.ts(23,10): error TS2678: Type 'boolean' is not comparable to type 'string | number'.
+
+
+==== tests/cases/conformance/types/typeRelationships/comparable/switchCaseWithUnionTypes01.ts (1 errors) ====
+    
+    var strOrNum: string | number;
+    var numOrBool: number | boolean;
+    var str: string;
+    var num: number;
+    var bool: boolean;
+    
+    switch (strOrNum) {
+        // Identical
+        case strOrNum:
+            break;
+    
+        // Constituents
+        case str:
+        case num:
+            break;
+    
+        // Overlap in constituents
+        case numOrBool:
+            break;
+    
+        // No relation
+        case bool:
+             ~~~~
+!!! error TS2678: Type 'boolean' is not comparable to type 'string | number'.
+            break;
+    }
\ No newline at end of file
diff --git a/tests/baselines/reference/switchCaseWithUnionTypes01.js b/tests/baselines/reference/switchCaseWithUnionTypes01.js
new file mode 100644
index 0000000000000..5c34ea674dc96
--- /dev/null
+++ b/tests/baselines/reference/switchCaseWithUnionTypes01.js
@@ -0,0 +1,48 @@
+//// [switchCaseWithUnionTypes01.ts]
+
+var strOrNum: string | number;
+var numOrBool: number | boolean;
+var str: string;
+var num: number;
+var bool: boolean;
+
+switch (strOrNum) {
+    // Identical
+    case strOrNum:
+        break;
+
+    // Constituents
+    case str:
+    case num:
+        break;
+
+    // Overlap in constituents
+    case numOrBool:
+        break;
+
+    // No relation
+    case bool:
+        break;
+}
+
+//// [switchCaseWithUnionTypes01.js]
+var strOrNum;
+var numOrBool;
+var str;
+var num;
+var bool;
+switch (strOrNum) {
+    // Identical
+    case strOrNum:
+        break;
+    // Constituents
+    case str:
+    case num:
+        break;
+    // Overlap in constituents
+    case numOrBool:
+        break;
+    // No relation
+    case bool:
+        break;
+}
diff --git a/tests/baselines/reference/switchCasesExpressionTypeMismatch.errors.txt b/tests/baselines/reference/switchCasesExpressionTypeMismatch.errors.txt
index de739af007d9b..26d39efef48ec 100644
--- a/tests/baselines/reference/switchCasesExpressionTypeMismatch.errors.txt
+++ b/tests/baselines/reference/switchCasesExpressionTypeMismatch.errors.txt
@@ -1,6 +1,6 @@
-tests/cases/compiler/switchCasesExpressionTypeMismatch.ts(4,10): error TS2322: Type 'typeof Foo' is not assignable to type 'number'.
-tests/cases/compiler/switchCasesExpressionTypeMismatch.ts(5,10): error TS2322: Type 'string' is not assignable to type 'number'.
-tests/cases/compiler/switchCasesExpressionTypeMismatch.ts(7,10): error TS2322: Type 'boolean' is not assignable to type 'number'.
+tests/cases/compiler/switchCasesExpressionTypeMismatch.ts(4,10): error TS2678: Type 'typeof Foo' is not comparable to type 'number'.
+tests/cases/compiler/switchCasesExpressionTypeMismatch.ts(5,10): error TS2678: Type 'string' is not comparable to type 'number'.
+tests/cases/compiler/switchCasesExpressionTypeMismatch.ts(7,10): error TS2678: Type 'boolean' is not comparable to type 'number'.
 
 
 ==== tests/cases/compiler/switchCasesExpressionTypeMismatch.ts (3 errors) ====
@@ -9,14 +9,14 @@ tests/cases/compiler/switchCasesExpressionTypeMismatch.ts(7,10): error TS2322: T
     switch (0) {
         case Foo: break;    // Error
              ~~~
-!!! error TS2322: Type 'typeof Foo' is not assignable to type 'number'.
+!!! error TS2678: Type 'typeof Foo' is not comparable to type 'number'.
         case "sss": break;  // Error
              ~~~~~
-!!! error TS2322: Type 'string' is not assignable to type 'number'.
+!!! error TS2678: Type 'string' is not comparable to type 'number'.
         case 123: break;    // No Error
         case true: break;   // Error
              ~~~~
-!!! error TS2322: Type 'boolean' is not assignable to type 'number'.
+!!! error TS2678: Type 'boolean' is not comparable to type 'number'.
     }
     
     var s: any = 0;
diff --git a/tests/baselines/reference/switchStatements.errors.txt b/tests/baselines/reference/switchStatements.errors.txt
index c99b0eba909a1..81e24aa69a823 100644
--- a/tests/baselines/reference/switchStatements.errors.txt
+++ b/tests/baselines/reference/switchStatements.errors.txt
@@ -1,4 +1,4 @@
-tests/cases/conformance/statements/switchStatements/switchStatements.ts(35,20): error TS2322: Type '{ id: number; name: string; }' is not assignable to type 'C'.
+tests/cases/conformance/statements/switchStatements/switchStatements.ts(35,20): error TS2678: Type '{ id: number; name: string; }' is not comparable to type 'C'.
   Object literal may only specify known properties, and 'name' does not exist in type 'C'.
 
 
@@ -39,8 +39,8 @@ tests/cases/conformance/statements/switchStatements/switchStatements.ts(35,20):
         case new D():
         case { id: 12, name: '' }:
                        ~~~~~~~~
-!!! error TS2322: Type '{ id: number; name: string; }' is not assignable to type 'C'.
-!!! error TS2322:   Object literal may only specify known properties, and 'name' does not exist in type 'C'.
+!!! error TS2678: Type '{ id: number; name: string; }' is not comparable to type 'C'.
+!!! error TS2678:   Object literal may only specify known properties, and 'name' does not exist in type 'C'.
         case new C():
     }
     
diff --git a/tests/baselines/reference/typeAssertions.errors.txt b/tests/baselines/reference/typeAssertions.errors.txt
index c7401e4fcf975..e330c23d737c3 100644
--- a/tests/baselines/reference/typeAssertions.errors.txt
+++ b/tests/baselines/reference/typeAssertions.errors.txt
@@ -1,11 +1,11 @@
 tests/cases/conformance/expressions/typeAssertions/typeAssertions.ts(5,5): error TS2346: Supplied parameters do not match any signature of call target.
-tests/cases/conformance/expressions/typeAssertions/typeAssertions.ts(31,12): error TS2352: Neither type 'SomeOther' nor type 'SomeBase' is assignable to the other.
+tests/cases/conformance/expressions/typeAssertions/typeAssertions.ts(31,12): error TS2352: Type 'SomeOther' cannot be converted to type 'SomeBase'.
   Property 'p' is missing in type 'SomeOther'.
-tests/cases/conformance/expressions/typeAssertions/typeAssertions.ts(35,15): error TS2352: Neither type 'SomeOther' nor type 'SomeDerived' is assignable to the other.
+tests/cases/conformance/expressions/typeAssertions/typeAssertions.ts(35,15): error TS2352: Type 'SomeOther' cannot be converted to type 'SomeDerived'.
   Property 'x' is missing in type 'SomeOther'.
-tests/cases/conformance/expressions/typeAssertions/typeAssertions.ts(37,13): error TS2352: Neither type 'SomeDerived' nor type 'SomeOther' is assignable to the other.
+tests/cases/conformance/expressions/typeAssertions/typeAssertions.ts(37,13): error TS2352: Type 'SomeDerived' cannot be converted to type 'SomeOther'.
   Property 'q' is missing in type 'SomeDerived'.
-tests/cases/conformance/expressions/typeAssertions/typeAssertions.ts(38,13): error TS2352: Neither type 'SomeBase' nor type 'SomeOther' is assignable to the other.
+tests/cases/conformance/expressions/typeAssertions/typeAssertions.ts(38,13): error TS2352: Type 'SomeBase' cannot be converted to type 'SomeOther'.
   Property 'q' is missing in type 'SomeBase'.
 tests/cases/conformance/expressions/typeAssertions/typeAssertions.ts(44,5): error TS2304: Cannot find name 'numOrStr'.
 tests/cases/conformance/expressions/typeAssertions/typeAssertions.ts(44,14): error TS1005: '>' expected.
@@ -58,23 +58,23 @@ tests/cases/conformance/expressions/typeAssertions/typeAssertions.ts(48,50): err
     someBase = <SomeBase>someBase;
     someBase = <SomeBase>someOther; // Error
                ~~~~~~~~~~~~~~~~~~~
-!!! error TS2352: Neither type 'SomeOther' nor type 'SomeBase' is assignable to the other.
+!!! error TS2352: Type 'SomeOther' cannot be converted to type 'SomeBase'.
 !!! error TS2352:   Property 'p' is missing in type 'SomeOther'.
     
     someDerived = <SomeDerived>someDerived;
     someDerived = <SomeDerived>someBase;
     someDerived = <SomeDerived>someOther; // Error
                   ~~~~~~~~~~~~~~~~~~~~~~
-!!! error TS2352: Neither type 'SomeOther' nor type 'SomeDerived' is assignable to the other.
+!!! error TS2352: Type 'SomeOther' cannot be converted to type 'SomeDerived'.
 !!! error TS2352:   Property 'x' is missing in type 'SomeOther'.
     
     someOther = <SomeOther>someDerived; // Error
                 ~~~~~~~~~~~~~~~~~~~~~~
-!!! error TS2352: Neither type 'SomeDerived' nor type 'SomeOther' is assignable to the other.
+!!! error TS2352: Type 'SomeDerived' cannot be converted to type 'SomeOther'.
 !!! error TS2352:   Property 'q' is missing in type 'SomeDerived'.
     someOther = <SomeOther>someBase; // Error
                 ~~~~~~~~~~~~~~~~~~~
-!!! error TS2352: Neither type 'SomeBase' nor type 'SomeOther' is assignable to the other.
+!!! error TS2352: Type 'SomeBase' cannot be converted to type 'SomeOther'.
 !!! error TS2352:   Property 'q' is missing in type 'SomeBase'.
     someOther = <SomeOther>someOther;
     
diff --git a/tests/baselines/reference/typeAssertionsWithIntersectionTypes01.errors.txt b/tests/baselines/reference/typeAssertionsWithIntersectionTypes01.errors.txt
new file mode 100644
index 0000000000000..42ed640e8fc29
--- /dev/null
+++ b/tests/baselines/reference/typeAssertionsWithIntersectionTypes01.errors.txt
@@ -0,0 +1,34 @@
+tests/cases/conformance/types/typeRelationships/comparable/typeAssertionsWithIntersectionTypes01.ts(17,9): error TS2352: Type 'I2' cannot be converted to type 'I1 & I3'.
+  Type 'I2' is not comparable to type 'I3'.
+    Property 'p3' is missing in type 'I2'.
+tests/cases/conformance/types/typeRelationships/comparable/typeAssertionsWithIntersectionTypes01.ts(18,9): error TS2352: Type 'I2' cannot be converted to type 'I3'.
+
+
+==== tests/cases/conformance/types/typeRelationships/comparable/typeAssertionsWithIntersectionTypes01.ts (2 errors) ====
+    interface I1 {
+        p1: number
+    }
+    
+    interface I2 extends I1 {
+        p2: number;
+    }
+    
+    interface I3 {
+        p3: number;
+    }
+    
+    var x = { p1: 10, p2: 20, p3: 30 };
+    var y: I1 & I3 = x;
+    var z: I2 = x;
+    
+    var a = <I1 & I3>z;
+            ~~~~~~~~~~
+!!! error TS2352: Type 'I2' cannot be converted to type 'I1 & I3'.
+!!! error TS2352:   Type 'I2' is not comparable to type 'I3'.
+!!! error TS2352:     Property 'p3' is missing in type 'I2'.
+    var b = <I3>z;
+            ~~~~~
+!!! error TS2352: Type 'I2' cannot be converted to type 'I3'.
+    var c = <I2>z;
+    var d = <I1>y;
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/typeAssertionsWithIntersectionTypes01.js b/tests/baselines/reference/typeAssertionsWithIntersectionTypes01.js
new file mode 100644
index 0000000000000..31fc831f95f81
--- /dev/null
+++ b/tests/baselines/reference/typeAssertionsWithIntersectionTypes01.js
@@ -0,0 +1,31 @@
+//// [typeAssertionsWithIntersectionTypes01.ts]
+interface I1 {
+    p1: number
+}
+
+interface I2 extends I1 {
+    p2: number;
+}
+
+interface I3 {
+    p3: number;
+}
+
+var x = { p1: 10, p2: 20, p3: 30 };
+var y: I1 & I3 = x;
+var z: I2 = x;
+
+var a = <I1 & I3>z;
+var b = <I3>z;
+var c = <I2>z;
+var d = <I1>y;
+
+
+//// [typeAssertionsWithIntersectionTypes01.js]
+var x = { p1: 10, p2: 20, p3: 30 };
+var y = x;
+var z = x;
+var a = z;
+var b = z;
+var c = z;
+var d = y;
diff --git a/tests/baselines/reference/typeAssertionsWithUnionTypes01.errors.txt b/tests/baselines/reference/typeAssertionsWithUnionTypes01.errors.txt
new file mode 100644
index 0000000000000..7bc2a9df9b3ad
--- /dev/null
+++ b/tests/baselines/reference/typeAssertionsWithUnionTypes01.errors.txt
@@ -0,0 +1,23 @@
+tests/cases/conformance/types/typeRelationships/comparable/typeAssertionsWithUnionTypes01.ts(14,9): error TS2352: Type 'I1' cannot be converted to type 'number'.
+
+
+==== tests/cases/conformance/types/typeRelationships/comparable/typeAssertionsWithUnionTypes01.ts (1 errors) ====
+    interface I1 {
+        p1: number
+    }
+    
+    interface I2 extends I1 {
+        p2: number;
+    }
+    
+    var x = { p1: 10, p2: 20 };
+    var y: number | I2 = x;
+    var z: I1 = x;
+    
+    var a = <number | I2>z;
+    var b = <number>z;
+            ~~~~~~~~~
+!!! error TS2352: Type 'I1' cannot be converted to type 'number'.
+    var c = <I2>z;
+    var d = <I1>y;
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/typeAssertionsWithUnionTypes01.js b/tests/baselines/reference/typeAssertionsWithUnionTypes01.js
new file mode 100644
index 0000000000000..9cc448f62176f
--- /dev/null
+++ b/tests/baselines/reference/typeAssertionsWithUnionTypes01.js
@@ -0,0 +1,27 @@
+//// [typeAssertionsWithUnionTypes01.ts]
+interface I1 {
+    p1: number
+}
+
+interface I2 extends I1 {
+    p2: number;
+}
+
+var x = { p1: 10, p2: 20 };
+var y: number | I2 = x;
+var z: I1 = x;
+
+var a = <number | I2>z;
+var b = <number>z;
+var c = <I2>z;
+var d = <I1>y;
+
+
+//// [typeAssertionsWithUnionTypes01.js]
+var x = { p1: 10, p2: 20 };
+var y = x;
+var z = x;
+var a = z;
+var b = z;
+var c = z;
+var d = y;
diff --git a/tests/cases/conformance/types/typeRelationships/comparable/equalityWithIntersectionTypes01.ts b/tests/cases/conformance/types/typeRelationships/comparable/equalityWithIntersectionTypes01.ts
new file mode 100644
index 0000000000000..74c0ebb7412e6
--- /dev/null
+++ b/tests/cases/conformance/types/typeRelationships/comparable/equalityWithIntersectionTypes01.ts
@@ -0,0 +1,24 @@
+interface I1 {
+    p1: number
+}
+
+interface I2 extends I1 {
+    p2: number;
+}
+
+interface I3 {
+    p3: number;
+}
+
+var x = { p1: 10, p2: 20, p3: 30 };
+var y: I1 & I3 = x;
+var z: I2 = x;
+
+if (y === z || z === y) {
+}
+else if (y !== z || z !== y) {
+}
+else if (y == z || z == y) {
+}
+else if (y != z || z != y) {
+}
\ No newline at end of file
diff --git a/tests/cases/conformance/types/typeRelationships/comparable/equalityWithUnionTypes01.ts b/tests/cases/conformance/types/typeRelationships/comparable/equalityWithUnionTypes01.ts
new file mode 100644
index 0000000000000..d83277b975a12
--- /dev/null
+++ b/tests/cases/conformance/types/typeRelationships/comparable/equalityWithUnionTypes01.ts
@@ -0,0 +1,20 @@
+interface I1 {
+    p1: number
+}
+
+interface I2 extends I1 {
+    p2: number;
+}
+
+var x = { p1: 10, p2: 20 };
+var y: number | I2 = x;
+var z: I1 = x;
+
+if (y === z || z === y) {
+}
+else if (y !== z || z !== y) {
+}
+else if (y == z || z == y) {
+}
+else if (y != z || z != y) {
+}
\ No newline at end of file
diff --git a/tests/cases/conformance/types/typeRelationships/comparable/switchCaseWithIntersectionTypes01.ts b/tests/cases/conformance/types/typeRelationships/comparable/switchCaseWithIntersectionTypes01.ts
new file mode 100644
index 0000000000000..fd629306b1041
--- /dev/null
+++ b/tests/cases/conformance/types/typeRelationships/comparable/switchCaseWithIntersectionTypes01.ts
@@ -0,0 +1,25 @@
+
+var strAndNum: string & number;
+var numAndBool: number & boolean;
+var str: string;
+var num: number;
+var bool: boolean;
+
+switch (strAndNum) {
+    // Identical
+    case strAndNum:
+        break;
+
+    // Constituents
+    case str:
+    case num:
+        break;
+
+    // Overlap in constituents
+    case numAndBool:
+        break;
+
+    // No relation
+    case bool:
+        break;
+}
\ No newline at end of file
diff --git a/tests/cases/conformance/types/typeRelationships/comparable/switchCaseWithUnionTypes01.ts b/tests/cases/conformance/types/typeRelationships/comparable/switchCaseWithUnionTypes01.ts
new file mode 100644
index 0000000000000..bdbfaf2df475c
--- /dev/null
+++ b/tests/cases/conformance/types/typeRelationships/comparable/switchCaseWithUnionTypes01.ts
@@ -0,0 +1,25 @@
+
+var strOrNum: string | number;
+var numOrBool: number | boolean;
+var str: string;
+var num: number;
+var bool: boolean;
+
+switch (strOrNum) {
+    // Identical
+    case strOrNum:
+        break;
+
+    // Constituents
+    case str:
+    case num:
+        break;
+
+    // Overlap in constituents
+    case numOrBool:
+        break;
+
+    // No relation
+    case bool:
+        break;
+}
\ No newline at end of file
diff --git a/tests/cases/conformance/types/typeRelationships/comparable/typeAssertionsWithIntersectionTypes01.ts b/tests/cases/conformance/types/typeRelationships/comparable/typeAssertionsWithIntersectionTypes01.ts
new file mode 100644
index 0000000000000..1afc760ef851a
--- /dev/null
+++ b/tests/cases/conformance/types/typeRelationships/comparable/typeAssertionsWithIntersectionTypes01.ts
@@ -0,0 +1,20 @@
+interface I1 {
+    p1: number
+}
+
+interface I2 extends I1 {
+    p2: number;
+}
+
+interface I3 {
+    p3: number;
+}
+
+var x = { p1: 10, p2: 20, p3: 30 };
+var y: I1 & I3 = x;
+var z: I2 = x;
+
+var a = <I1 & I3>z;
+var b = <I3>z;
+var c = <I2>z;
+var d = <I1>y;
diff --git a/tests/cases/conformance/types/typeRelationships/comparable/typeAssertionsWithUnionTypes01.ts b/tests/cases/conformance/types/typeRelationships/comparable/typeAssertionsWithUnionTypes01.ts
new file mode 100644
index 0000000000000..3010c5f159a76
--- /dev/null
+++ b/tests/cases/conformance/types/typeRelationships/comparable/typeAssertionsWithUnionTypes01.ts
@@ -0,0 +1,16 @@
+interface I1 {
+    p1: number
+}
+
+interface I2 extends I1 {
+    p2: number;
+}
+
+var x = { p1: 10, p2: 20 };
+var y: number | I2 = x;
+var z: I1 = x;
+
+var a = <number | I2>z;
+var b = <number>z;
+var c = <I2>z;
+var d = <I1>y;