Used to connect two simple propositions, "∧" means "and", which is equivalent to the intersection of sets. The true value of the proposition P∧Q is related to the true values of P and Q. When both P and Q are true propositions, the proposition P∧Q is true and others are false propositions. "∨" means or, which is equivalent to the union of sets.

Logical symbols are all kinds of artificial language symbols used to express logical forms and logical operations in logic. Traditional formal logic uses some logical symbols to express the logical form of thinking. For example, "all S are P" means the logical form of full-name affirmative proposition, "M-P, S-M, so s-p" means the logical form of syllogism, and so on. In modern formal logic, namely mathematical logic, logical symbols are more widely used. Not only variables, but also logical constants are represented by symbols. For example, "V", "A", "One", 1 and "One" respectively mean disjunction, conjunction, implication, negation and equivalence.