Example using PL Sentences

From the sentence "Heads I win, tails you lose," prove that "I win."
First, define the axioms in KB:
1. "Heads I win, tails you lose."
  (Heads => IWin) or, equivalently, (~Heads v IWin)
  (Tails => YouLose) or, equivalently, (~Tails v YouLose)
2. Add some general knowledge axioms about coins, winning, and losing:
  (Heads v Tails)
  (YouLose => IWin) or, equivalently, (~YouLose v IWin)
  (IWin => YouLose) or, equivalently, (~IWin v YouLose)
Goal: IWin
Proof:

Sentence 1 Sentence 2 Resolvent

~IWin ~Heads v IWin ~Heads

~Heads Heads v Tails Tails

Tails ~Tails v YouLose YouLose

YouLose ~YouLose v IWin IWin

IWin ~IWin False