How to check if entries in columns in matrix can (only) have opposite signs in Matlab

What I am interested in seeing is if there is an easy way to show that a large set of matrices (cannot) have columns where there is 1 positive number and 1 negative number. Therefore, I would want to take the following matrix and return false:

[    0, p1_2,    0, p1_4,     0,  p1_4,    0, p1_4,     0]
[ p2_1,    0,    0,    0, -p2_1, -p2_1,    0,    0, -p2_1]
[ p3_1, p3_2, p3_3,    0,     0,     0, p3_2, p3_3,  p3_3]
[    0,    0, p4_3, p4_4,  p4_4,     0, p4_4,    0,     0]

As one can see, from column 6 (6), we have p1_4 and p2_1 being the same sign. From (9) we have p2_1 and p3_3 the same sign. However from (8) we would have p1_4 and p3_3 being opposite signs and so this fails.

Any ideas on doing? Thanks! (Btw, I am working in matlab)