The open interval between $a$ and $b$ is the subposet of $P$ induced by the elements $z$ such that $p < z < q$. If $a$ and $b$ are incomparable, then an error is thrown.
i1 : P = booleanLattice 3; |
i2 : openInterval(P, "001", "111") o2 = Relation Matrix: | 1 0 | | 0 1 | o2 : Poset |
The object openInterval is a method function.