Singular Book 2.1.34 -- minimal presentations, prune

i1 : R = QQ[x,y,z,MonomialOrder=>{Weights=>{-1,-1,-1},RevLex},Global=>false]

o1 = R

o1 : PolynomialRing

i2 : M = cokernel matrix{{0,y},{x*y-1,x*z},{x*y+1,x*z}}

o2 = cokernel | 0     y  |
              | -1+xy xz |
              | 1+xy  xz |

                            3
o2 : R-module, quotient of R

i3 : null -- prune M -- doesn't work yet

i4 : stderr << "--this example doesn't work yet" << endl;
--this example doesn't work yet