Minimal graphs with disjoint dominating and paired-dominating sets

A subset $D\subseteq V_G$ is a dominating set of $G$ if every vertex in $V_G-D$ has a~neighbor $D$, while $D$ paired-dominating a~dominating and the subgraph induced by contains perfect matching. graph $D\!P\!D\!P$-graph it pair $(D,P)$ disjoint sets vertices such that $P$ $G$. The study $D\!P\!D\!P$-graphs was initiated Southey Henning (Cent. Eur. J. Math. 8 (2010) 459--467; Comb. Optim. 22 (2011) 217--234). In this paper, we provide conditions which ensure $D\!P\!D\!P$-graph. particular, characterize minimal $D\!P\!D\!P$-graphs.