Answer to Question #243818 in Discrete Mathematics for Latha

Question

Verify the validity of the argument: All lions are fierce. Some lions do not drink coffee. Hence some fierce creatures do not drink coffee.” (Lewis Carrol)

Answer 1

-By the second premise, we have that there is a lion that does not drink coffee, let it be Leo

-Using simplification we can tell that Leo is a lion.

-Now using modus ponens on the first premise we know that Leo is fierce.

-So Leo is fierce and doesn't drink coffee.

-Now using existential generalization, we can say that there exists creature that is fierce, and does not drink coffee.

Hence the argument is valid