ly correct bijection between higher-order abstract syntax (HOAS) and the natural numbers enables one to define a "not equals" relationship between terms and also to have ...
The pattern-avoiding fillings of Young diagrams we study arose from Postnikov’s work on positive Grassman cells. They are called Γ -diagrams, and are in bijection with decorate...
Abstract. We present bijections between four classes of combinatorial objects. Two of them, the class of unlabeled (2 + 2)-free posets and a certain class of involutions (or chord ...