On the semigroup of partial isometries of a finite chain

Rotimi Kehinde, Abdullahi Umar

Let ${\mathcal{I}}_n$ be the symmetric inverse semigroup on $X_n=\{1,2,...,n\}$ and let ${\mathcal{DP}}_n$ and ${\mathcal{O}\mathcal{DP}}_n$ be its subsemigroups of partial isometries and of order-pres…