definition option_eqType : eqType → eqType ≝ λd:eqType.mk_eqType ? ? (ocmpP d).
definition option_canonical_eqType : ∀d:eqType.d → option_eqType d ≝
λd:eqType.λx:d.(Some ? x : sort (option_eqType d)).
definition option_eqType : eqType → eqType ≝ λd:eqType.mk_eqType ? ? (ocmpP d).
definition option_canonical_eqType : ∀d:eqType.d → option_eqType d ≝
λd:eqType.λx:d.(Some ? x : sort (option_eqType d)).