diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 590eceeb302..c3edfed4804 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -4329,7 +4329,7 @@ namespace ts {
          * @param relationFlags Additional information affecting whether the relation holds. Currently used only for distinguishing 
          * between a type comparison when extending classes from other comparisons of the constructor types.
          * 
-         * Caution: checks triggered by these flags should NOT affect the result re
+         * Caution: checks triggered by these flags should NOT affect the result cached.
          * @param errorNode The node upon which all errors will be reported, if defined.
          * @param headMessage If the error chain should be prepended by a head message, then headMessage will be used.
          * @param containingMessageChain A chain of errors to prepend any new errors found.
@@ -4388,6 +4388,7 @@ namespace ts {
             // Ternary.False if they are not related.
             function isRelatedTo(source: Type, target: Type, reportErrors?: boolean, headMessage?: DiagnosticMessage): Ternary {
                 let result: Ternary;
+                let relationFlagCheckResult: Ternary;
                 // both types are the same - covers 'they are the same primitive type or both are Any' or the same type parameter cases
                 if (source === target) return Ternary.True;
                 if (relation !== identityRelation) {
diff --git a/src/compiler/core.ts b/src/compiler/core.ts
index 7b35c5e0d65..c3d2a00eba5 100644
--- a/src/compiler/core.ts
+++ b/src/compiler/core.ts
@@ -2,17 +2,19 @@
 
 /* @internal */
 namespace ts {
-    // Ternary values are defined such that
-    // x & y is False if either x or y is False.
-    // x & y is Maybe if either x or y is Maybe, but neither x or y is False.
-    // x & y is True if both x and y are True.
-    // x | y is False if both x and y are False.
-    // x | y is Maybe if either x or y is Maybe, but neither x or y is True.
-    // x | y is True if either x or y is True.
+    /**
+     * Ternary values are defined such that
+     * x & y is False if either x or y is False.
+     * x & y is Maybe if either x or y is Maybe, but neither x or y is False.
+     * x & y is True if both x and y are True.
+     * x | y is False if both x and y are False.
+     * x | y is Maybe if either x or y is Maybe, but neither x or y is True.
+     * x | y is True if either x or y is True.
+     */
     export const enum Ternary {
         False = 0,
         Maybe = 1,
-        True  = -1
+        True = -1
     }
 
     export function createFileMap<T>(getCanonicalFileName: (fileName: string) => string): FileMap<T> {