Multiplicatively idempotent HSI algebras satisfy all equations of $\mathbb{N}$

Tumadhir Alsulami, Marcel Jackson, Michael Kinyon

An algebra with binary operations $+,\cdot ,\uparrow$ and constant $1$ is called an HSI algebra if it satisfies the basic commutative semiring laws for $+,\cdot ,1$ on~$\mathbb{N}$ a…