Consider the argument form p rightarrow tilde q q rightarrow

Consider the argument form: p rightarrow tilde q q rightarrow tilde p therefore p vee q Use the truth table below to determine whether this form of argument is valid or invalid. Include a truth table and a few words explaining how the truth table supports your answer.

Solution

It is not valid since the premises (p then not q) and (q and not p) are true ( ine last row) but (p or q) is false.

The argument is valid if (p or q) is true whenever all the premises are true.