TermBuilder.Equiv
val code_is_contr : t m -> t m
val code_fiber : t m -> t m -> t m -> t m -> t m
val code_equiv : t m -> t m -> t m
val equiv_fwd : t m -> t m
val equiv_inv : t m -> t m -> t m
val equiv_inv_path : t m -> t m -> t m -> t m