As can be seen in the examples section, if A is an n×n Lehmer matrix and B is an m×m Lehmer matrix, then A is a submatrix of B whenever m>n.
In the given examples, if A is an n×n Lehmer matrix and B is an m×m Lehmer matrix, then A can be considered as a submatrix of B when the size of B (m) is greater than the size of A (n).