Thursday, August 3 2000
Quiz 8
Name: _______________________________
B & C
------ and-Elim
B B --> A
--------------- ->-Elim
A
A B | (A v B) -> A
--------------------------
T T | T
T F | T
F T | F
F F | T
The propositional formula is not a tautology.
Gamma entails S, i.e., whenever all formulas in Gamma are true,
S is also true.
Gottlob Frege (1848 - 1924).
It means, "there exists a natural number which is less or equal all
natural numbers". The sentence is true since there is a
smallest natural number, namely 1.