In mathematics, a Heyting algebra is a bounded lattice equipped with a binary operation a → b of implication such that ≤ b is equivalent to c ≤. Wikipedia

A bounded lattice, L, modified to serve as a model for a logical calculus by being equipped with a binary operation called "implies", denoted → (sometimes ⊃ or ⇒), defined such that (a→b)∧a ≤ b and, moreover, that x = a→b is the greatest element such that x∧a ≤ b (in the sense that if c∧a ≤ b then c ≤ a→b). Wiktionary

Bounded lattice equipped with operation called implies. Wiktionary (translation)