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 nIn = \x:set.\y:set.~ x iIn y term TransSet = \x:set.!y:set.y iIn x -> Subq y x const Pi : set (set set) set term setexp = \x:set.\y:set.Pi y \z:set.x const SNo : set prop const mul_SNo : set set set term * = mul_SNo infix * 2291 2290 axiom SNo_mul_SNo: !x:set.!y:set.SNo x -> SNo y -> SNo (x * y) const SNoLt : set set prop term < = SNoLt infix < 2020 2020 const Empty : set const real : set const SNoLev : set set const ordsucc : set set const omega : set const SNoS_ : set set const abs_SNo : set set const add_SNo : set set set term + = add_SNo infix + 2281 2280 const minus_SNo : set set term - = minus_SNo const eps_ : set set lemma !x:set.!y:set.Empty < x -> Empty < y -> ~ x * y iIn real -> SNo x -> SNoLev x iIn ordsucc omega -> x iIn SNoS_ (ordsucc omega) -> x < omega -> (!z:set.z iIn SNoS_ omega -> (!w:set.w iIn omega -> abs_SNo (z + - x) < eps_ w) -> z = x) -> SNo y -> SNoLev y iIn ordsucc omega -> y iIn SNoS_ (ordsucc omega) -> y < omega -> (!z:set.z iIn SNoS_ omega -> (!w:set.w iIn omega -> abs_SNo (z + - y) < eps_ w) -> z = y) -> (!z:set.z iIn omega -> !P:prop.(!w:set.w iIn SNoS_ omega -> Empty < w -> w < x -> x < w + eps_ z -> P) -> P) -> (!z:set.z iIn omega -> !P:prop.(!w:set.w iIn SNoS_ omega -> Empty < w -> w < y -> y < w + eps_ z -> P) -> P) -> ~ SNo (x * y) var x:set var y:set hyp Empty < x hyp Empty < y hyp ~ x * y iIn real hyp SNo x hyp SNoLev x iIn ordsucc omega hyp x iIn SNoS_ (ordsucc omega) hyp x < omega hyp !z:set.z iIn SNoS_ omega -> (!w:set.w iIn omega -> abs_SNo (z + - x) < eps_ w) -> z = x hyp SNo y hyp SNoLev y iIn ordsucc omega hyp y iIn SNoS_ (ordsucc omega) hyp y < omega hyp !z:set.z iIn SNoS_ omega -> (!w:set.w iIn omega -> abs_SNo (z + - y) < eps_ w) -> z = y hyp !z:set.z iIn omega -> ?w:set.w iIn SNoS_ omega & (w < y & y < w + eps_ z) hyp !z:set.z iIn omega -> !P:prop.(!w:set.w iIn SNoS_ omega -> Empty < w -> w < x -> x < w + eps_ z -> P) -> P claim ~ !z:set.z iIn omega -> !P:prop.(!w:set.w iIn SNoS_ omega -> Empty < w -> w < y -> y < w + eps_ z -> P) -> P