extractPTermNames (PLet _ _ n _ p1 p2 p3) = n : concatMap extract [p1, p2, p3]
extractPTermNames (PLet _ _ n _ p1 p2 p3) = n : concatMap extract [p1, p2, p3]
extractPTermNames (PLet _ _ n _ p1 p2 p3) = n : concatMap extract [p1, p2, p3]