We have these axioms and modus ponens:
Axiom 1 is: P→(Q→P)
Axiom 2 is: (P→(Q→R))→((P→Q)→(P→R))
Axiom 3 is:(P→Q)→(¬Q→¬P)
Modus ponens is: from P and P→Q infer Q
Edit: I still couldn't solve it, so I would really appreciate it if someone gave me a hint
Using these axioms and modus penons I want to infer V from (U → V ), (¬U→V)
Using axiom 3 I said that (V→ (U → V ) ) → (¬ (U →V ) → ¬V ). And using axiom 1 I said that V→ (U → V ). So using modus ponens we can infer that ¬ (U →V ) → ¬V.
If I could somehow write ¬ (U →V ) using one of these axioms then I could infer ¬V.
I'm a bit stuck here. Any help please?