vb. 1. to fulfil the conditions of a given theorem, assumption, etc. For example, x = 3 satisfies the equation x² - 4x + 3 = 0. 2. (Logic) to yield a truth by the substitution of the given value or sequence of values in a predicate. For example, x killed y is satisfied by the ordered pair 〈Cassius, Caesar〉, but not by the pair 〈Caesar, Cassius〉; it is also defined to be satisfied by any longer sequence, including infinite sequences, of which the initial segment is identical. This enables a uniform semantic account to be given of relations and predicates, and by an extension due to Tarski, also to closed sentences regarded as zero-place predicates. Semantics for the existential and universal quantifier can be given in terms of satisfaction by sequences which agree everywhere except in the position corresponding to the bound variable.