“…Compared to the large number of references to continuous Lyapunov-type inequalities, little has been done for discrete Lyapunov-type inequalities. Let us list the works in which the Lyapunov-type inequality appears in a discrete context: for difference equations see [9][10][11][18][19][20][21]31], for discrete systems see [15,16,26,27,29,30,32], for fractional discrete problems see [12][13][14] and for problems on time scales (as these kind of problems include difference equations) see [1][2][3][4][5][6]17,24].…”