- Usage:
`isDegenerate X`

- Function: isDegenerate
- Inputs:
`X`, a normal toric variety

- Outputs:
- a Boolean value, that is true if the fan of
`X`is contained in a proper linear subspace of its ambient space

- a Boolean value, that is true if the fan of

A *d*-dimensional normal toric variety is degenerate if its rays do not span *ℚ ^{d}*. For example, projective spaces and Hirzebruch surfaces are not degenerate.

i1 : assert not isDegenerate toricProjectiveSpace 3 |

i2 : assert not isDegenerate hirzebruchSurface 7 |

Although one typically works with non-degenerate toric varieties, not all normal toric varieties are non-degenerate.

i3 : U = normalToricVariety ({{4,-1,0},{0,1,0}},{{0,1}}); |

i4 : isDegenerate U o4 = true |

- Basic invariants and properties of normal toric varieties
- rays(NormalToricVariety) -- get the rays of the associated fan