(map,Module,Nothing,List)

map(M,,v) -- construct a map from a free graded module to M whose entries are obtained from the doubly-nested list v of ring elements.

The absence of the second argument indicates that the source of the map is to be a free module constructed with an attempt made to assign degrees to its basis elements so as to make the map homogeneous of degree zero.

i1 : R = ZZ/101[x,y]



o1 = R



o1 : PolynomialRing

i2 : f = map(R^2,,{{x^2,y^2},{x*y,0}})



o2 = {0} | x2 y2 |

     {0} | xy 0  |



             2       2

o2 : Matrix R  <--- R

i3 : degrees source f



o3 = {{2}, {2}}



o3 : List

i4 : isHomogeneous f



o4 = true