Consistency checks (same as in Container).
Container
M : Accessors_generic with type (a, b, c) options := (a, b, c) Options.t with type (a, b) t := (a, b) T.t with type (a, b) tree := (a, b) Tree.t with type a elt := a Elt.t with type cmp cmp := cmp Cmp.t
Options : T.T3
Cmp : T.T1
Elt : T.T1
Tree : T.T2
T : T.T2