Uniform critical sets in Latin squares

Diane Donovan1, Abdollah Khodkar1
1Centre for Discrete Mathematics and Computing Department of Mathematics The University of Queensland Queensland 4072 Australia

Abstract

In this paper, we introduce two new classes of critical sets, \( t \)-uniform and \( T \)-uniform (where \( t \) is a positive integer and \( T \) is a partial Latin square). We identify, up to isomorphism, all \( t \)-uniform critical sets of order \( n \), where \( 2 \leq n \leq 6 \). We show that the completable product of two \( T \)-uniform critical sets is a \( T \)-uniform critical set for certain partial Latin squares \( T \), and then apply this theorem to small examples to generate infinite families of \( T \)-uniform critical sets.