Section BoolSpec.
Variable elt elt' elt'' : Type.
Implicit Types m : t elt.
Implicit Types x y z : key.
Implicit Types e : elt.
Hint Resolve add_neq_o : map.
Hint Resolve remove_eq_o : map.
Hint Resolve remove_neq_o : map.

Lemma map2_1bis : forall (m: t elt)(m': t elt') x
(f:option elt->option elt'->option elt''),
f None None = None ->
find x (map2 f m m') = f (find x m) (find x m').