Make Equal fail typechecking with todo

failing typechecking makes the fact that the problems are correctly sovled more obvious and more satisfying, even if it means more errors when opening a new file

Author: gvergnaud

helpers.ts

@@ -1,15 +1,9 @@
-type _Equal<X, Y> = (<T>() => T extends X ? 1 : 2) extends <T>() => T extends Y
+export type Equal<X, Y> = (<T>() => T extends X ? 1 : 2) extends <T>() => T extends Y
   ? 1
   : 2
   ? true
   : false;
 
-export type Equal<X, Y> = _Equal<X, TODO> extends true
-  ? true
-  : _Equal<X, symbol> extends true
-  ? true
-  : _Equal<X, Y>;
-
 export type Expect<T extends true> = T;
 
 export type Tuple = [any, ...any[]];