All maximal congruences on an inverse semigroup of fence-preserving transformations

Abstract

We study the inverse semigroup of all partial injections on an \(n\)-element set \(\{1,...,n\}\), which preserve the zig-zag order \(1\prec 2\succ 3\prec 4\succ \cdots n\) and the parity for some positive integer \(n\). We characterize all maximal congruences on this inverse semigroup, which are entirely congruences of index two.