On the volumes and affine types of trades

E. Ghorbani, S. Kamali, G. B. Khosrovshahi +1

A $[t]$-trade is a pair $T=(T_{+},T_{-})$ of disjoint collections of subsets (blocks) of a $v$-set $V$ such that for every $0\le i\le t$, any $i$-subset of $V$ is included in the same…