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NormalToricVarieties :: isDegenerate(NormalToricVariety)

isDegenerate(NormalToricVariety) -- whether a toric variety is degenerate

Synopsis

Description

A d-dimensional normal toric variety is degenerate if its rays do not span 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

See also