--
-- Helper functions typically needed by type rules
--


--
-- If a can be made equal to b, it does so and returns true. Otherwise it
-- returns false.
--

let equal = \a b -> abstract equal inputs a, b
                      ( inst (derivation outputs res
                                { branch equal:   a == b;
                                                  this.res == true;
                                  branch unequal: this.res == false;
                                }) as test;
                        establish test;
                        test.res
                      );