Math Logic Drawing Conclusions and Laws Flashcards
1
Q
Law Of Modus Tollens
A
P→q
-q
——
-P is true
In a true conditional, when a conclusion is false, the hypothesis must also be false
2
Q
Law Of Detachment
A
P→q
P
——
Q is true
True hypothesis needs to have true conclusion to be true
3
Q
Conjunctive simplification
A
p^q
p is true q is true
Both have to be true in a conjunction
4
Q
Law of contrapositive
A
P→Q
-Q→-P is true
If you get a sentence that is a true statement, the contrapositive of the statement always has a valid conclusion.
5
Q
Disjunctive Inference
A
Pvq
-P
——
Q is true
When a disjunction is true and one of them is false, the other one must be true
6
Q
Chain Law
A
P→Q
Q→R
——-
P→R is true
7
Q
DeMorgan’s Law #1
A
-(P^Q)
-Pv-Q is true
8
Q
DeMorgan’s Law #2
A
-(PvQ)
-P^-Q is true