phi 9 Flashcards
what is a ~
-Negation: it is not the case that…
what is a &
-Conjunction: Both _ and _
What is a V
-Disjunction: either _ or _
what is a –>
- Conditional: If _ then _
what is a <–>
-Biconditional: _ if and only if _
what are conjucts
parts of the conjunction
anytime you see the word but you
cross it out and put and because we treat them as logically equivalent
conjunctions are symmetrical
you can switch the order of the conjuncts and still have a true conclusion
when using neither or nor
you must use a negation 2 disjuncts with parentheses around them
what are the antecedent and consequent
antecedent comes 1st
consequent comes after
valid forms with conditional
Modus Ponens
when you have a conditional on the 1st premise, the antecedent on the following premise and the consequent as the conclusion
P1: A->B
P2: A
C: B
Modus Tollens
when you have a conditional on the 1st premise, the negation of the consequent on the following premise and the negation of the antecedent as the conclusion
P1: A->B
P2: ~B
C: ~A
formal fallacies
Affirming the Consequent
when you have a conditional on the 1st premise, the consequent on the following premise and the antecedent as the conclusion
P1: A->B
P2: B
C: A
Denying the Antecedent
when you have a conditional on the 1st premise, the negation of the antecedent on the following premise and the negation of the consequent as the conclusion
P1: A->B
P2: ~A
C: ~B
when you see unless
cross it out and write if not
what is a tautology
when the column under the main connective has t on ever row
what is a contradiction
when the column under the main connective has f on every row
