pseudoforest
...that in graph theory, a pseudoforest can contain trees and pseudotrees, but cannot contain any butterflies, diamonds, handcuffs, or bicycles?
...that in <a href="./Graph_theory" id="mwEs4" rel="mw:WikiLink" title="Graph theory">graph theory</a>, a <b id="mwEs8"><a href="./Pseudoforest" id="mwEtA" rel="mw:WikiLink" title="Pseudoforest">pseudoforest</a></b> can contain <a href="./Tree_(graph_theory)" id="mwEtE" rel="mw:WikiLink" title="Tree (graph theory)">trees</a> and pseudotrees, but cannot contain any butterflies, diamonds, handcuffs, or bicycles?