Definition:Heyting Algebra

Definition
Let $(L, \wedge, \vee, \preceq)$ be a lattice.

Then $(L, \wedge, \vee, \preceq)$ is a Heyting algebra or a Heyting lattice iff


 * $(L, \wedge, \vee, \preceq)$ is a Brouwerian lattice.
 * $L$ has a smallest element.