Recent content by johnsmiths

Homework Statement Suppose that a mathematical expression can only be formed by the following symbols: 0, 1, 2, …, 9, ×, +, /. Some examples are “0 + 9”; “2 + 2 × 8”; “1 / 5 + 6”. Let an be the the number of such mathematical expression of length n (e.g. “0 + 9” is considered of length 3)...

It means p\leftrightarrowq is a tautology. Maybe I make some mistakes with my question. And after I know that, what should I do next? Just guessing or there is a systematic way to work out the solution.

What do you mean is finding something \rightarrow ( p\veeq ) and make it a tautology?

Homework Statement find a logical expression using only ∧ and ¬ operators which is logically equivalent to (p ∨ q) The Attempt at a Solution losing direction what should I first consider? There is another question about recurrent relation. Suppose that a mathematical expression can...