N-free posets and orthomodularity
Gejza Jenča
Abstract
We prove that the incomparability orthoset of a finite poset is Dacey if and only if the poset is N-free. We give a characterization of finite posets with compatible incomparability orthosets.
Gejza Jenča
We prove that the incomparability orthoset of a finite poset is Dacey if and only if the poset is N-free. We give a characterization of finite posets with compatible incomparability orthosets.
This paper contains 11 sections, 9 theorems, 16 equations, 2 figures.
Lemma 2.3
Let $(O,\perp)$ be an orthoset. Let $X,Y$ be subsets of $O$. Then $X$ is orthoclosed and $Y=X^\perp$ if and only if $X\perp Y$ and for every $z\in O\setminus(X\cup Y)$ there are $x\in X$, $y\in Y$ such that $z\not\perp x$ and $z\not\perp y$.