smallDiagonal -- Ideal of the small diagonal in (P^1)^n

Usage:

I = smallDiagonal n

I = smallDiagonal S
Inputs:
- n, an integer, number of factors of P^1
- S, a ring, ring with 2n vars, corresponding to (P^1)^n for some n
Outputs:
- I, an ideal, ideal of the small diagonal

Description

i1 : smallDiagonal 3

o1 = ideal (- x   x    + x   x   , - x   x    + x   x   , - x   x    +
               1,0 0,1    0,0 1,1     1,0 0,2    0,0 1,2     1,1 0,2  
     ------------------------------------------------------------------------
     x   x   )
      0,1 1,2

                ZZ
o1 : Ideal of -----[x   , x   , x   , x   , x   , x   ]
              32003  0,0   1,0   0,1   1,1   0,2   1,2

i2 : S = productOfProjectiveSpaces 3

o2 = S

o2 : PolynomialRing

i3 : smallDiagonal S

o3 = ideal (- x   x    + x   x   , - x   x    + x   x   , - x   x    +
               1,0 0,1    0,0 1,1     1,0 0,2    0,0 1,2     1,1 0,2  
     ------------------------------------------------------------------------
     x   x   )
      0,1 1,2

o3 : Ideal of S

Ways to use smallDiagonal:

smallDiagonal(Ring)
smallDiagonal(ZZ)

For the programmer

The object smallDiagonal is a method function.

The source of this document is in K3Carpets.m2:1857:0.

smallDiagonal -- Ideal of the small diagonal in (P^1)^n

Description

See also

Ways to use smallDiagonal:

For the programmer