Anyone know propositional logic??

Is anyone on this forum any good with propositional logic??
I have a problem that I need to solve with a propositional logic tree but I just can't solve it.

If someone is willing to help me please say so and I will post the problem.

>>1
Forget it, it's NP-complete.

Just post it already.

this is it

(P1=>P2)=>(P3vP4vP5) |-> (P4=>P1)=>(P3vP5vP1)

I know its possible to solve but I can't do it. Good luck anyone that trys

Yeah you should just post it

Assume (P4 => P1)
  Assume ~(P3vP5vP1)
    ~P3 ^ ~P5 ^ ~P1
    we know (P1=>P2)=>(P3vP4vP5)
    Assume ~P4
      ~P3 ^ ~P5 ^ ~P4
      ~(P3vP4vP5)
      thus ~(P1=>P2)
      thus P1 ^ ~P2
      P1 ^ ~P1, contradiction
    P4
    P4 => P1, thus P1
    P1 ^ ~P1, contradiction
  P3vP5vP1
(P4=>P1) => (P3vP5vP1)