const In : set set prop term iIn = In infix iIn 2000 2000 term Subq = \x:set.\y:set.!z:set.z iIn x -> z iIn y term TransSet = \x:set.!y:set.y iIn x -> Subq y x term ordinal = \x:set.TransSet x & !y:set.y iIn x -> TransSet y var x:set var y:set var z:set hyp y iIn x hyp TransSet x hyp !w:set.w iIn x -> TransSet w hyp z iIn y claim z iIn x -> TransSet z