1 paper
Camino Balbuena, Hortensia Galeana-Sánchez, Mukuy-kak Guevara
Let D=(V,A) be a digraph and consider an arc subset A′⊆A and an exhaustive mapping ϕ:A→A′ such that (i) the set of heads of A′ is H(A′)=V; (ii) the map f…