Signature.CONVThe type of conversion modules from one version to another.
module V_from : sig ... endmodule V_to : sig ... endval public_key_hash : V_from.Public_key_hash.t -> V_to.Public_key_hash.tval public_key : V_from.Public_key.t -> V_to.Public_key.tval secret_key : V_from.Secret_key.t -> V_to.Secret_key.t