This is an interactive website to help you learn how to write a logic proof. You should try to fill in the rules yourself, and use the information on this webpage to check your work or to get a hint if you need one.

You will write similar proofs in your homework. Click on the empty boxes to reveal the rules.

But before you click, try to fill in the rules yourself and figure out what will appear!

If you wish to make the text disappear again, refresh the page.

 $$1.\ (J\cdot K)\rightarrow L$$ $$2.\ (J\rightarrow L)\rightarrow M$$ $$3.\ \sim K \vee N$$ $$/ \therefore K\rightarrow (M\cdot N)$$ $$4.\ (K\cdot J)\rightarrow L$$ 1 Com. $$5.\ K\rightarrow (J\rightarrow L)$$ 4 Exp. $$6.\ K\rightarrow M$$ 5, 2 H.S. $$7.\ \sim K \vee M$$ 6 Impl. $$8.\ (\sim K \vee M)\cdot (\sim K \vee N)$$ 7, 3 Conj. $$9.\ \sim K \vee (M\cdot N)$$ 8, Dist. $$10.\ K \rightarrow (M\cdot N)$$ 9 Impl.