theorem Th28: :: GOBRD11:28

for G being empty-yielding X_equal-in-line Y_equal-in-column Matrix of (TOP-REAL 2) holds cell (G,(len G),(width G)) = { |[r,s]| where r, s is Real : ( (G * ((len G),1)) `1 <= r & (G * (1,(width G))) `2 <= s ) }