Hindley-Milner algorithm: using types to ensure bindings are applied...

Prolog is vs = with lists...

Given a substitution S and list Xs, how to apply S to Xs...

Pattern matching equivalent variables in Haskell, like in Prolog...

Prolog Code Example: Unification...

Seemingly unnecessary case in the unification algorithm in SICP...

Simplest example of need for "unification" in type inference...

Type inference to unification problem...