User:KBlott/Questions

$(\mathbb N \times \mathbb N, \wedge)$ is a semilattice. $(\mathbb N \times \mathbb N, \vee)$ is a semilattice. Does the first absorption law hold for the protointegers? Does the second absorption law hold for the protointegers? Is $\mathbb N \times \mathbb N$ a lattice?