Introduction - If you have any usage issues, please Google them yourself
Enter a first order language must start and end brackets. For example, (@ a (P (a)). The application of mathematical logic: first-order through the C language sign language to judge bound only P, Q, R become members of symbols restricted to a, b, c proposition symbols :& ,|,~,-( implication), = (equal) quantifier symbols: universal quantifier: @ existential quantifier:#