3) The Semantics of Propositional Logic Flashcards
1
Q
Truth Conditions for and
A
2
Q
Truth Conditions for or
A
3
Q
Truth conditions for —>
A
4
Q
Truth conditions for <—>
A
5
Q
What are logically true sentences called
A
Tautologies
6
Q
Truth table for ‘neither…nor…’
A
7
Q
What is a Semantic counter-example
A
Something proves the opposite e.g. all apple are green, here is a blue apple.
8
Q
What is semantic consistency?
A
Iff there is a sentence structure that proves the sentence (L1) to be correct
9
Q
What is a contradiction?
A
Iff A is not true under any L1 sentence (i.e. you want there to be only false arguments
10
Q
What is logically true?
A
A sentence A is logically true iff A is true under all L1 structures
