Answer with the abbreviation for the RL derivation rule (EI, EE, Al, AE, QN). Suppose (3x) Lx is a premise in the proof, next suppose that La is assumed (where a is foreign to the proof), then suppose that (3x)(Vy)Sxy is derived in the subproof using the RL derivation rules, what rule would allow you to derive (3x)(Vy)Sxy from (3x) Lx and subproof ending in (3x)(Vy) Sxy