# pp1ProductFan -- the fan of n products of PP^1

## Synopsis

• Usage:
F = pp1ProductFan n
• Inputs:
• Outputs:
• F, an instance of the type Fan

## Description

Generates the fan of the product of $n$ projective one-spaces. This is the same as the normal fan of the $n$ dimensional hypercube.

 i1 : F = pp1ProductFan 2 o1 = {ambient dimension => 2 } number of generating cones => 4 number of rays => 4 top dimension of the cones => 2 o1 : Fan i2 : apply(maxCones F, rays) o2 = {| -1 0 |, | 1 0 |, | 1 0 |, | -1 0 |} | 0 -1 | | 0 -1 | | 0 1 | | 0 1 | o2 : List

## Ways to use pp1ProductFan :

• "pp1ProductFan(ZZ)"

## For the programmer

The object pp1ProductFan is .