rank

rank M -- computes the rank of the module M.

     i1 = R = ZZ/101[x,y,z]
     
     o1 = R
     
     o1 : PolynomialRing

     i2 = p = vars R;
     
                  1       3
     o2 : Matrix R  <--- R

     i3 = rank kernel p
     
     o3 = 2

     i4 = rank cokernel p
     
     o4 = 0