# describe(MultirationalMap) -- describe a multi-rational map

## Synopsis

• Function: describe
• Usage:
describe Phi
? Phi
• Inputs:
• Phi,
• Outputs:
• a description of Phi

## Description

? Phi is a lite version of describe Phi. The latter has a different behavior than describe(RationalMap), since it performs computations.

 i1 : Phi = multirationalMap graph rationalMap PP_(ZZ/65521)^(1,4); o1 : MultirationalMap (rational map from 4-dimensional subvariety of PP^4 x PP^5 to PP^4 x PP^5) i2 : time ? Phi -- used 0.000121582 seconds o2 = multi-rational map consisting of 2 rational maps source variety: 4-dimensional subvariety of PP^4 x PP^5 cut out by 9 target variety: PP^4 x PP^5 ------------------------------------------------------------------------ hypersurfaces of multi-degrees (1,1)^8 (0,2)^1 i3 : image Phi; o3 : ProjectiveVariety, 4-dimensional subvariety of PP^4 x PP^5 i4 : time ? Phi -- used 0.000180359 seconds o4 = multi-rational map consisting of 2 rational maps source variety: 4-dimensional subvariety of PP^4 x PP^5 cut out by 9 hypersurfaces of multi-degrees (1,1)^8 (0,2)^1 target variety: PP^4 x PP^5 dominance: false image: 4-dimensional subvariety of PP^4 x PP^5 cut out by 9 hypersurfaces of multi-degrees (1,1)^8 (0,2)^1  i5 : time describe Phi -- used 1.74763 seconds o5 = multi-rational map consisting of 2 rational maps source variety: 4-dimensional subvariety of PP^4 x PP^5 cut out by 9 hypersurfaces of multi-degrees (1,1)^8 (0,2)^1 target variety: PP^4 x PP^5 base locus: empty subscheme of PP^4 x PP^5 dominance: false image: 4-dimensional subvariety of PP^4 x PP^5 cut out by 9 hypersurfaces of multi-degrees (1,1)^8 (0,2)^1 multidegree: {51, 51, 51, 51, 51} degree: 1 degree sequence (map 1/2): [(1,0), (0,2)] degree sequence (map 2/2): [(0,1), (2,0)] coefficient ring: ZZ/65521 i6 : time ? Phi -- used 0.000322812 seconds o6 = multi-rational map consisting of 2 rational maps source variety: 4-dimensional subvariety of PP^4 x PP^5 cut out by 9 hypersurfaces of multi-degrees (1,1)^8 (0,2)^1 target variety: PP^4 x PP^5 base locus: empty subscheme of PP^4 x PP^5 dominance: false image: 4-dimensional subvariety of PP^4 x PP^5 cut out by 9 hypersurfaces of multi-degrees (1,1)^8 (0,2)^1 multidegree: {51, 51, 51, 51, 51} degree: 1