Logical And

Both statements must be true. In p ∧ q, the whole statement is true only when p and q are both true. In every other case it is false. Logicians call this operation conjunction, and the symbol is often called the wedge.

The wedge was first printed for conjunction in 1930, in a paper where the Dutch mathematician Arend Heyting formalized intuitionistic logic. Intuitionistic logic is a version of logic that accepts a statement only when there is a proof of it. Earlier logicians wrote conjunction in other ways, such as a dot or &. ∧ was one choice of notation that later caught on, and it did not replace the others everywhere.

Today, logic textbooks and computer-science courses use ∧ in truth tables and formulas. Programming languages mostly use && or and, because these are easy to type and each language sets its own rules for how they are evaluated.