Recent content by Movingon

Thanks. Yeah what I meant was describing more precisely and formally a language generated by a certain grammar, the Chomsky hierarchy I already know of. For example, you are given a grammar as follows: G = ({S, X}, {a, b}, P, S) with the rules: P = {S → aaSbb | X | ε, X → Xb | ε}. where ε...

Ok I have a simple question. Let us say we have a formal grammar, let us take this simple example: S → aSb S → ab This grammar generates language a^n b^n. My question is, is there a way I can tell what kind of language this generates from the rules? I can of course apply the rules and...

That was my mistake. Thanks for the correction. It should be \ p \vee \neg r? So are my attempts at solutions correct? Since 1 and 3 are a tautology, they are right. The 2 is false, because it is not a tautology?

Prove the validity of the following: 1. It rains, Ali is sick. Ali was not sick. ⊢ It didn't rain. 2. I like maths, I study. I study or don't make an exam. ⊢ I don't make an exam, I do not like Maths. 3. I study, I do not fail in maths. I don't play soccer, I study. I failed in maths...