Originally Posted by

**Cermak** I've been working on a proof for my symbolic logic class, but I cannot seem to solve it. Even after hours and hours of work I am pretty stuck. Anyone want to take a crack at it? It's probably easy for experts. Our class has been working with Hurley's 18 rules

I'm not sure what convention everyone is used to around here, so i'll post a key.

> = If then,

* = Conjuction,

~ = Negation

v= Or

C: will precede the conclusion/goal of the proof

Okay, here is the proof:

C: I

1. (I>E)>C

2. C > ~C

I can't seem to solve it.

There are a few obvious lines (and about a hundred others) I've found are useful right off the bat.

3. ~C v ~C 2, Material Implication

4. ~C 3, Tautology

Can anyone help me solve this? I've tried a million things. It's truly my "white whale" of our logic problem set.