# Example of a finite Heyting algebra that is not Boolean

Simple question: what are some simple examples of a finite Heyting Algebras, that is not also a Boolean Algebra?

The Heyting implication is defined by \begin{align*} U\rightarrow V &= \bigcup\{W\text{ open}\mid U \cap W \subseteq V\}\\ &= (U^c\cup V)^\circ,\end{align*} where $$X^c$$ is the complement of $$X$$ and $$Y^\circ$$ is the interior of $$Y$$.