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: forall y_1: R_4(y_1) or ~Q_20(y_1). Q_20(a_10).
exists x: Q_20(x) can be inferred via the existential generalization rule. forall y_1: Q_20(y_1) -> R_4(y_1) can be inferred via the universal rewriting rule.