This is an optional argument for the pushFwd function. Its default value is false, which means that the presentation of a pushed forward module is pruned by default. If NoPrune is set to true, then the prune calls in pushFwd are turned off.
i1 : R5=QQ[a..e]
o1 = R5
o1 : PolynomialRing
i2 : R6=QQ[a..f]
o2 = R6
o2 : PolynomialRing
i3 : M=coker genericMatrix(R6,a,2,3)
o3 = cokernel | a c e |
| b d f |
2
o3 : R6-module, quotient of R6
i4 : G=map(R6,R5,{a+b+c+d+e+f,b,c,d,e})
o4 = map (R6, R5, {a + b + c + d + e + f, b, c, d, e})
o4 : RingMap R6 <-- R5
i5 : notpruned = pushFwd(G,M,NoPrune => true)
o5 = cokernel {0} | e c 0 a-b-d 0 0 0 0 |
{0} | 0 d 0 b+d de be bc-ad+bd+cd+d2 0 |
{1} | 0 0 c -1 0 -e 0 -de |
{1} | 1 0 d 1 -c -a+b+c+d+e c+d bc-ad+bd+cd+d2+de |
4
o5 : R5-module, quotient of R5
i6 : pruned = pushFwd(G,M)
o6 = cokernel | c -de |
| d bc-ad+bd+cd+d2+de |
2
o6 : R5-module, quotient of R5