(** * Properties of the dataflow analysis *)

Lemma analyze_successors:
forall f env bsh an pc bs s e,
analyze f env bsh = Some an ->
bsh!pc = Some bs ->
In s (successors_block_shape bs) ->
an!!pc = OK e ->
exists e', transfer f env bsh s an!!s = OK e' /\ EqSet.Subset e' e.