Import Int. Variable a : Int Variable P : Int -> Int -> Bool Variable f : Int -> Int -> Int Variable g : Int -> Int Axiom H1 : P (f a (g a)) (f a (g a)) Axiom H2 : P (f (g a) (g a)) (f (g a) (g a)) Axiom H3 : P (f (g a) (g a)) (g a) Theorem T1 : exists x y : Int, P (f y x) (f y x) := ExistsIntro _ (ExistsIntro _ H1) Theorem T2 : exists x : Int, P (f x (g x)) (f x (g x)) := ExistsIntro _ H1 Theorem T3 : exists x : Int, P (f x x) (f x x) := ExistsIntro _ H2 Theorem T4 : exists x : Int, P (f (g a) x) (f x x) := ExistsIntro _ H2 Theorem T5 : exists x : Int, P x x := ExistsIntro _ H2 Theorem T6 : exists x y : Int, P x y := ExistsIntro _ (ExistsIntro _ H3) Theorem T7 : exists x : Int, P (f x x) x := ExistsIntro _ H3 Theorem T8 : exists x y : Int, P (f x x) y := ExistsIntro _ (ExistsIntro _ H3) Show Environment 8.