verifySagbi -- Test if the generators form sagbi basis

Synopsis

• Usage:

  result = verifySagbi subR

• Inputs:
  • subR, an instance of the type Subring,
• Outputs:
  • result, an instance of the type Subring, a copy of subR with the isSAGBI flag correctly set.

Description

i1 : R = QQ[x,y,z];

i2 : L = subring {y*(x-1), y*x^2, y*(x^3+x^2+x+1), y^2};

i3 : L#"isSAGBI"

o3 = false

i4 : L = verifySagbi L;

i5 : L#"isSAGBI"

o5 = true

i6 : M = verifySagbi {x+y+z,x*y+x*z+y*z, x*y*z, (x-y)*(x-z)*(y-z)};

i7 : M#"isSAGBI"

o7 = false

i8 : N = verifySagbi {x+y+z, x*y+x*z+y*z, x*y*z};

i9 : N#"isSAGBI"

o9 = true