strcmp bug failed to define properly in env

Summary:
Failed to match properly and def wouldn't be stored in the environment
at all. This particularly clear when create the 'fun' lambda like so:
def {fun} (\ {args body} {def (head args) (\ (tail args) body)})

and then trying to use it failed to save the new fun into the
environment.
fun {add-together x y} {+ x y}