Before going into R/T, know your logical proofs:

[laconicsax]

http://www.smbc-comics.com/index.php?db=comics&id=2135

[trotsky]

1. Awesome.

But there's one used most frequently of all in there:

1. If P, then Q.
2. How DARE you be an uppity fundie atheist posting in the RELIGION forum!!!!

[charlie]

2. And

1. If P, then Unicorns.
2. NO?
3. Why do you think they call it faith? Harrumph!

[laconicsax]

4. There's also this one:

1. If P, then Q
2. Not Q, therefore G

And my personal favorite:

1. If P, then Q
2. If R, then S
3. Not S, therefore not P

[LeftishBrit]

3. ROFL!!! Thanks!

Useful for many purposes, I'd say.

[Deep13]

5. Right, exactly. nt

[laconicsax]

6. Here's another good one:

Proof by faith.

-If P, then Q
-Not Q
-Therefore P