Logic

• Sep 9th 2011, 10:30 AM
taylorrodriguezNWC
Logic
I am very confused with logic, and the difference between, disjunctions and conjunctions, and where you would put perenthesis, and things like that. Does any one know a easy way to learn it, or can walk me through it.

• Sep 9th 2011, 10:33 AM
DrSteve
Re: Logic
I think it would be helpful if you posted a specific question.
• Sep 9th 2011, 01:52 PM
taylorrodriguezNWC
Re: Logic
how do you tell the difference between a disjunction, conjustion, negation, and a biconditional?
• Sep 9th 2011, 02:19 PM
emakarov
Re: Logic
Quote:

how do you tell the difference between a disjunction, conjustion, negation, and a biconditional?
There are couple of ways to look at this. The difference between conjunction and disjunction is similar to the difference between multiplication and addition. Both * and + are functions of two arguments, but they, obviously, in general return different results for the same arguments. While * and + can be considered as functions of natural numbers, conjunction /\ and disjunction \/ are functions that take and return 0 or 1. In fact, multiplication returns the same result as conjunction on {0, 1}.

Also, you understand the difference between "and" (conjunction) and "or" (disjunction) in the natural language, don't you?

Concerning parentheses, there is an order of operations for functions on {0, 1}, just as there is an order for functions on integers. The usual order is: negation, conjunction, disjunction, implication, biconditional.