ExtDegreeLimit(ZZ,Matrix,Module,ZZ) -- Computes the map Ext^i(target f,N)_{<=d} -> Ext^i(source f,N)_{<=d} induced by f.

Synopsis

Usage:
g=ExtDegreeLimit(i,f,N,d)
Function: ExtDegreeLimit
Inputs:
- i, an integer
- f, a matrix
- N, a module
- d, an integer
Optional inputs:
- printTimings => ..., -- a Boolean value, default value false, whether to print timings of the key steps of the function.
Outputs:
- g, a matrix

If N is an ideal or ring, it is regarded as a module in the evident way.

i1 : R = ZZ/32003[a..d];

i2 : I = monomialCurveIdeal(R,{1,3,4});

o2 : Ideal of R

i3 : M1 = R^1/I;

i4 : M2 = R^1/ideal(I_0,I_1);

i5 : f = inducedMap(M1,M2);

o5 : Matrix

i6 : time prune ExtDegreeLimit(2,f,R^1,0)
     -- used 0.0213874 seconds

o6 = {-5} | -d2 -cd c2 |

o6 : Matrix