1 bot : * => ([A : *] -> A)
3 not [A : *] : * => (A -> bot)
5 P [A : *] : * => (A -> *)
7 U : * => ([X : *] -> (P (P X) -> X) -> P (P X))
9 tau [t : P (P U)] : U => (
10 \X f p => t (\x => p (f (x X f)))
13 sigma [s : U] : P (P U) => (s U (\t => tau t))
16 \y => not ([p : P U] -> sigma y p -> p (tau (sigma y)))
20 tau (\p => [x : U] -> sigma x p -> p x)
24 [p : P U] -> sigma Omega p -> p (tau (sigma Omega))
27 lem1 [p : P U] [H1 : [x : U] -> sigma x p -> p x] : p Omega => (
28 H1 Omega (\x => H1 (tau (sigma x)))
32 lem1 Delta (\x H2 H3 => H3 Delta H2 (\p => H3 (\y => p (tau (sigma y)))))
36 \p => lem1 (\y => p (tau (sigma y)))
39 loop : bot => (lem2 lem3)