CT M5A2: Constructing Truth Tables Discussion

Professor’s post

Sean Choi posted Mar 12, 2018 1:01 PM

Subscribe

Did I say that last week we were "in the weeds"? Well, this week is going to be harder still - but we can all get through with a bit of help. To that end, I will offer some helpful tips for memorizing the truth tables for our logical operators, as well as providing a link to a YouTube video which provides further information about how to use those operators.

For negations, just remember that it switches the truth value of the original statement. So, if p were true, then not-p would be false; and if p were false, then not-p would be true.

For conjunctions, just remember that a conjunction is true when both conjuncts are true, and false otherwise. So, p and q is true when both p and q are true, and false otherwise. 

For disjunctions, just remember that a disjunction is true when at least one disjunct is true, and false otherwise. So, p or q is true when either p or q is true, and false otherwise.

For the conditional, just remember that a conditional is true when either its antecedent (the part after the "if...") is false or the consequent (the part after the "then...") is true, and false otherwise. So, if p then q is true when either p is false, or q is true.

For the biconditional, just remember that a biconditional is true when both sides of the biconditional agree in truth value, and is false otherwise. So, p if and only if q is true when p is true and q is true, or p is false and q is false, and is false otherwise.

Here is now a link [ https://www.youtube.com/watch?v=4mS5MO-p0g8&t=83s ] to the promise video on the truth tables. (If you need additional help, by all means seek out other helpful videos about truth tables on YouTube!)