const In : set set prop term iIn = In infix iIn 2000 2000 const PNo_upc : (set (set prop) prop) set (set prop) prop const PNoLt : set (set prop) set (set prop) prop term PNo_rel_strict_lowerbd = \P:set (set prop) prop.\x:set.\p:set prop.!y:set.y iIn x -> !q:set prop.PNo_upc P y q -> PNoLt x p y q const PNo_downc : (set (set prop) prop) set (set prop) prop term PNo_rel_strict_upperbd = \P:set (set prop) prop.\x:set.\p:set prop.!y:set.y iIn x -> !q:set prop.PNo_downc P y q -> PNoLt y q x p term PNo_rel_strict_imv = \P:set (set prop) prop.\Q:set (set prop) prop.\x:set.\p:set prop.PNo_rel_strict_upperbd P x p & PNo_rel_strict_lowerbd Q x p const ordsucc : set set term PNo_rel_strict_split_imv = \P:set (set prop) prop.\Q:set (set prop) prop.\x:set.\p:set prop.PNo_rel_strict_imv P Q (ordsucc x) (\y:set.p y & y != x) & PNo_rel_strict_imv P Q (ordsucc x) \y:set.p y | y = x term PNoEq_ = \x:set.\p:set prop.\q:set prop.!y:set.y iIn x -> (p y <-> q y) term PNo_rel_strict_uniq_imv = \P:set (set prop) prop.\Q:set (set prop) prop.\x:set.\p:set prop.PNo_rel_strict_imv P Q x p & !q:set prop.PNo_rel_strict_imv P Q x q -> PNoEq_ x p q 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 term PNoLt_pwise = \P:set (set prop) prop.\Q:set (set prop) prop.!x:set.ordinal x -> !p:set prop.P x p -> !y:set.ordinal y -> !q:set prop.Q y q -> PNoLt x p y q term nIn = \x:set.\y:set.~ x iIn y term PNoLt_ = \x:set.\p:set prop.\q:set prop.?y:set.y iIn x & (PNoEq_ y p q & ~ p y & q y) term PNoLe = \x:set.\p:set prop.\y:set.\q:set prop.PNoLt x p y q | x = y & PNoEq_ x p q axiom ordsuccI2: !x:set.x iIn ordsucc x axiom PNoEq_ref_: !x:set.!p:set prop.PNoEq_ x p p axiom PNoLtI3: !x:set.!y:set.!p:set prop.!q:set prop.y iIn x -> PNoEq_ y p q -> ~ p y -> PNoLt x p y q axiom PNoLeI1: !x:set.!y:set.!p:set prop.!q:set prop.PNoLt x p y q -> PNoLe x p y q axiom PNoLe_upc: !P:set (set prop) prop.!x:set.!y:set.!p:set prop.!q:set prop.ordinal x -> ordinal y -> PNo_upc P x p -> PNoLe x p y q -> PNo_upc P y q axiom FalseE: ~ False lemma !P:set (set prop) prop.!Q:set (set prop) prop.!x:set.!p:set prop.!y:set.PNo_upc Q x p -> ordinal x -> y iIn x -> PNoEq_ y p (\z:set.!q:set prop.PNo_rel_strict_imv P Q (ordsucc z) q -> q z) -> ~ p y -> (!q:set prop.PNo_rel_strict_imv P Q (ordsucc y) q -> q y) -> ordinal y -> ordinal (ordsucc y) -> PNo_rel_strict_lowerbd Q (ordsucc y) (\z:set.!q:set prop.PNo_rel_strict_imv P Q (ordsucc z) q -> q z) -> ~ PNoLt (ordsucc y) (\z:set.!q:set prop.PNo_rel_strict_imv P Q (ordsucc z) q -> q z) y p var P:set (set prop) prop var Q:set (set prop) prop var x:set var y:set var p:set prop var z:set hyp !w:set.w iIn x -> ordsucc w iIn x hyp !w:set.w iIn x -> PNo_rel_strict_uniq_imv P Q w \u:set.!q:set prop.PNo_rel_strict_imv P Q (ordsucc u) q -> q u hyp PNo_upc Q y p hyp ordinal y hyp z iIn y hyp z iIn x hyp PNoEq_ z p \w:set.!q:set prop.PNo_rel_strict_imv P Q (ordsucc w) q -> q w hyp ~ p z hyp !q:set prop.PNo_rel_strict_imv P Q (ordsucc z) q -> q z hyp ordinal z hyp ordinal (ordsucc z) claim ordsucc z iIn x -> PNoLt x (\w:set.!q:set prop.PNo_rel_strict_imv P Q (ordsucc w) q -> q w) y p