DEFINITION 8 Matrices 矩阵 Let a=ail and b= bil be m X n zero-one matrices. Then the join ofA and B is the zero-one matrix with (i, jth entry aibi the join of A and b is denoted by AVB. The meet of A and B is the zero-one matrix with (i, j)th entry a i A bir The meet of A and B is denoted by A∧BM a t r i c e s 矩 阵 DEFINITION 8. Let A = [aij] and B = [bij] be m × n zero-one matrices. Then the join of A and B is the zero-one matrix with (i, j)th entry aij∨bij. The join of A and B is denoted by A∨B. The meet of A and B is the zero-one matrix with (i, j)th entry aij∧bij. The meet of A and B is denoted by A∧B