witt(ZZ,QuotientRing) -- Forms the n-th Witt ring of a quotient ring

Function: witt (missing documentation)
Usage:

witt(n, R)
Inputs:
- n, an integer,
- R, a quotient ring,
Outputs:
- an instance of the type WittQuotientRing,

Description

Given an integer $n \geq 1$ and a quotient ring R of positive prime characteristic, this produces the n-th witt ring $W_n(R)$ of R.

Note that for this method to work, the ambient ring of R must be a polynomial ring. If this is not the case, consider flattening before applying witt.

i1 : R = (ZZ/3)[x,y,z] / ideal(x^2, y^2, z^2);

i2 : WR = witt(2, R)

o2 = Witt (R)
         2

o2 : WittQuotientRing

i3 : S = (ZZ/2)[x,y,z] / ideal(x^2);

i4 : R = S / ideal(y^2, z^2);

i5 : WR = witt(2, (flattenRing R)#0)

             ZZ
             --[x..z]
              2
o5 = Witt (------------)
         2   2   2   2
           (y , z , x )

o5 : WittQuotientRing

Ways to use this method:

witt(ZZ,QuotientRing) -- Forms the n-th Witt ring of a quotient ring

The source of this document is in WittVectors/Documentation.m2:166:0.