On the mutual visibility in Cartesian products and triangle-free graphs

Serafino Cicerone, Gabriele Di Stefano, Sandi Klavzar

Given a graph $G=(V(G),E(G))$ and a set $P\subseteq V(G)$, the following concepts have been recently introduced: $(i)$ two elements of $P$ are \emph{mutually visible} if there is…