fact: Definition not_impl3 := λ"t" λ"f" "f" @ (callcc @ "t") @ (callcc @ (λ"g" "t" @ λ"a" "g")) @ (callcc @ (λ"g" "t" @ λ"a" λ"b" "g")) @ λ"d" "t" @ λ"a" λ"b" λ"c" "d".
imports: ClassicalRealizability.Tactics ClassicalRealizability.BasicResults ClassicalRealizability.Subtyping