Critical Kernel Imperfectness in $4$-quasi-transitive and $4$-anti-transitive digraphs of small diameter

Germán Benítez-Bobadilla, Hortensia Galeana-Sánchez, César Hernández-Cruz

A kernel in a digraph is an independent and absorbent subset of its vertex set. A digraph is critical kernel imperfect if it does not have a kernel, but every proper induced subdig…