(In reply to re: Boolean
by Dej Mar)
Under the supposition that 1 is true and the rest false:
(A) "either 1 or 4 is true" is true
(B) "2 is false" is true
Stating that "if and only if (B) then (A)" is then true, as both are true. But the supposition was that this statement (3) is false. The supposition is contradicted.
Posted by Charlie
on 2007-05-17 12:18:34