validity - an arguement is valid if the premises are true

if there are cracks in the premise then the validity test fails

soundness - the test to see if the argument is valid and all premises are true

if P implies Q, then P is called the antecedent and Q is called the consequent. In some contexts, the consequent is called the apodosis.

modus ponen - if p then q ; not p ; not q.

disjunctive syllogism - either p or q ; not q ; therefore it's p