Section REDUCE.
Variable A: Type.
Variable f: (valnum -> option rhs) -> A -> list valnum -> option (A * list valnum).
Variable V: Type.
Variable ge: genv.
Variable sp: val.
Variable rs: regset.
Variable m: mem.
Variable sem: A -> list val -> option V.
Hypothesis f_sound:
forall eqs valu op args op' args',
(forall v rhs, eqs v = Some rhs -> rhs_eval_to valu ge sp m rhs (valu v)) ->
f eqs op args = Some(op', args') ->
sem op' (map valu args') = sem op (map valu args).
Variable n: numbering.
Variable valu: valnum -> val.
Hypothesis n_holds: numbering_holds valu ge sp rs m n.

Lemma reduce_sound:
forall op rl vl op' rl' res,
reduce A f n op rl vl = (op', rl') ->
map valu vl = rs##rl ->
sem op rs##rl = Some res ->
sem op' rs##rl' = Some res.