obj GenericOpType =  op(AnyIn)->(AnyOut);
obj AnyIn =  any;
obj AnyOut =  any;

obj MoreSpecificOpType extends GenericOpType
    where: AnyIn = MoreSpecificInType;
	   AnyOut = MoreSpecificInType;
end;

obj MoreSpecificInType extends AnyIn =  integer and integer and integer;
obj MoreSpecificOutType extends AnyIn =  integer and integer;

op AnOpOfAMoreSpecificType(MoreSpecificInType)->(MoreSpecificOutType);
op AnotherOpOfAMoreSpecificType(integer,integer,integer)->(integer,integer);
(*
 * Note: both of the preceding ops match MoreSpecificOpType, the former
 * obviously, and the latter by the parm unbundling rule.
 *)

val mo1:MoreSpecificOpType = AnOpOfAMoreSpecificType;
val mo2:MoreSpecificOpType = AnotherOpOfAMoreSpecificType;