It is necessary that all multi-forms in the old coefficient ring F can be automatically coerced into the new coefficient ring K.
i1 : Phi = inverse first graph rationalMap PP_QQ^(2,2); o1 : MultirationalMap (birational map from PP^5 to 5-dimensional subvariety of PP^5 x PP^5) |
i2 : describe Phi o2 = multi-rational map consisting of 2 rational maps source variety: PP^5 target variety: 5-dimensional subvariety of PP^5 x PP^5 cut out by 8 hypersurfaces of multi-degree (1,1) base locus: surface in PP^5 cut out by 6 hypersurfaces of degree 2 dominance: true multidegree: {1, 3, 9, 23, 51, 102} degree: 1 degree sequence (map 1/2): [1] degree sequence (map 2/2): [2] coefficient ring: QQ |
i3 : K = ZZ/65521; |
i4 : Phi' = Phi ** K; o4 : MultirationalMap (birational map from PP^5 to 5-dimensional subvariety of PP^5 x PP^5) |
i5 : describe Phi' o5 = multi-rational map consisting of 2 rational maps source variety: PP^5 target variety: 5-dimensional subvariety of PP^5 x PP^5 cut out by 8 hypersurfaces of multi-degree (1,1) base locus: surface in PP^5 cut out by 6 hypersurfaces of degree 2 dominance: true multidegree: {1, 3, 9, 23, 51, 102} degree: 1 degree sequence (map 1/2): [1] degree sequence (map 2/2): [2] coefficient ring: K |
i6 : Phi'' = Phi ** frac(K[t]); o6 : MultirationalMap (birational map from PP^5 to 5-dimensional subvariety of PP^5 x PP^5) |
i7 : describe Phi'' o7 = multi-rational map consisting of 2 rational maps source variety: PP^5 target variety: 5-dimensional subvariety of PP^5 x PP^5 cut out by 8 hypersurfaces of multi-degree (1,1) base locus: surface in PP^5 cut out by 6 hypersurfaces of degree 2 dominance: true multidegree: {1, 3, 9, 23, 51, 102} degree: 1 degree sequence (map 1/2): [1] degree sequence (map 2/2): [2] coefficient ring: frac(K[t]) |