lsubst n new (LApp t e args) = let e' = lsubst n new e
                                   args' = map (lsubst n new) args in
                                   LApp t e' args'
lsubst n new (LApp t e args) = let e' = lsubst n new e
                                   args' = map (lsubst n new) args in
                                   LApp t e' args'
lsubst n new (LApp t e args) = let e' = lsubst n new e
                                   args' = map (lsubst n new) args in
                                   LApp t e' args'