#[global]
Hint Resolve cons_Cmp : core.
#[local] Ltac caseq :=
match goal with [ |- context [match ?t with _ => _ end] ] =>
let cmp := fresh in
let H := fresh in
remember t as cmp eqn:H; symmetry in H; destruct cmp
end.

Lemma compare_Cmp : forall m1 m2,
Cmp (compare_aux (Raw.cons m1 (Raw.End _), Raw.cons m2 (Raw.End _)))
(Raw.elements m1) (Raw.elements m2).