3 problems

Let $CMRM(m,n,c)$ be a chordal $m$-ring mixed graph on vertex set $\mathbb Z_m\times\mathbb Z_n$, with the arcs and chords defined by the source, and let $k$ be an even diameter sa…

Let $CRM(N,c)$ be a chordal ring mixed graph with vertex set $\mathbb Z_N$, directed-cycle arcs $i\mathbin{\rightarrow}i+1$, and chords determined by the odd parameter $c$ as in th…

Let $CR(N,c)$ be a chordal ring graph with diameter $k$, and let $N(k)$ denote the maximum number of vertices among chordal ring graphs of diameter $k$. For even $k>2$, the conject…