Definition modlu (v w: aval) :=
match w, v with
| L i2, L i1 =>
if Int64.eq i2 Int64.zero
then if va_strict tt then Vbot else ntop
else L (Int64.modu i1 i2)
| _, _ => ntop2 v w
end.

Lemma modlu_sound:
forall v w u x y, vmatch v x -> vmatch w y -> Val.modlu v w = Some u -> vmatch u (modlu x y).