isMember(MultirationalMap,RAT) -- test membership in a hom-set of rational maps

Synopsis

• Function: isMember

• Usage:

  member(Phi,H)

• Inputs:
  • Phi, a multi-rational map
  • H, a hom-set
• Outputs:
  • a Boolean value, whether Phi is in the hom-set H

Description

i1 : s = segreEmbedding PP_(ZZ/13)^{1,2};

o1 : MultirationalMap (rational map from PP^1 x PP^2 to PP^5)

i2 : (X,Y) = (source s,target s);

i3 : member(s,Hom(X,Y))

o3 = true

i4 : member(s,Hom(X ** X,Y))

o4 = false

i5 : member(s,Hom(X,))

o5 = true

i6 : member(s,Hom(,))

o6 = true

i7 : assert(o3 and (not o4) and o5 and o6)

See also

• Hom(MultiprojectiveVariety,MultiprojectiveVariety) -- get the hom-set of rational maps between two multi-projective varieties