Ring _ ZZ -- get a ring variable by index

Synopsis

• Operator: _

• Usage:

  R_i

• Inputs:
  • R, a ring
  • i, an integer
• Outputs:
  • a ring element, the i-th generator of the ring R

Description

i1 : R = ZZ[a..d]

o1 = R

o1 : PolynomialRing

i2 : R_2

o2 = c

o2 : R

If the coefficient ring is a polynomial ring, then the numbering matches that in the list returned by generators.

i3 : S = R[x,y,z]

o3 = S

o3 : PolynomialRing

i4 : generators(S,CoefficientRing=>ZZ)

o4 = {x, y, z, a, b, c, d}

o4 : List

i5 : S_2

o5 = z

o5 : S

i6 : S_6

o6 = d

o6 : S

See also

• generators -- provide matrix or list of generators
• Ring _ String -- get a ring variable by name