MathDB
remaining table ommiting a column in nxn table has no two rows the same

Source: 1979 Hungary - Kürschák Competition p3

October 15, 2022
combinatorics

Problem Statement

An n×nn \times n array of letters is such that no two rows are the same. Show that it must be possible to omit a column, so that the remaining table has no two rows the same.