What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Name the inference rule being used: exists y: W_4(y) or ~S_1(y). forall y: W_4(y) <-> S_1(y).
exists y: S_1(y) -> W_4(y) can be inferred via the existential rewriting rule. forall y: W_4(y) -> S_1(y) can be inferred via the universal biconditional elimination rule. forall y: S_1(y) -> W_4(y) can be inferred via the universal biconditional elimination rule.