K-Chorded bigraph

[math]\displaystyle{ k }[/math]-Chorded bigraph --- [math]\displaystyle{ k }[/math]-хордовый двудольный граф.

A bigraph is mathcalled [math]\displaystyle{ k }[/math]-chorded if each of its non- quad cycle has at least [math]\displaystyle{ k }[/math] chords (so, for example, a 4-chorded bigraph has no 6-cycles, induced or not, and an [math]\displaystyle{ \infty }[/math]-chorded bigraph has no non-quad cycles, induced or not).