A conditional event algebra (CEA) is an algebraic structure whose domain consists of logical objects described by statements of forms such as "If A, then B," "B, given A," and "B, in case A." Unlike the standard Boolean algebra of events, a CEA allows the defining of a probability function, P, which satisfies the equation P(If A then B) = P(A and B) / P(A) over a usefully broad range of conditions.