## Rule Index

We’ve finished all of the rules but the two proof applications, so I thought I would do a quick rundown of how each rule works. No guest arguments today, this is going to be a lightning round of symbols and… Continue Reading

## DeMorgan’s

A Lesson in Logic Here we are, our final substitution rule, and the only one named after a person, rather than a function. Named after Augustus DeMorgan, this rule, which is actually two rolled into one, and can look a… Continue Reading

## Exportation

Not just what your country’s economy is based on, nor a criticism of free trade, but a new substitution rule. Our second last, in fact. If you’ve been following along, you’ve learned almost all of the essential rules of two-value… Continue Reading

## Biconditional Exchange

A Lesson in Logic It’s a long weekend here in Canada, and I’m close to finishing a draft, so here’s a quick and straightforward substitution rule for you, so you can get on with your weekend. Remember the biconditional? The… Continue Reading

## Distribution

A Lesson in Logic We’re down to the last few substitution rules, but they get stranger and harder from here. I’ve always found distribution a little counter-intuitive (to the point where I nearly messed up the truth table for today)… Continue Reading