Variety -- the class of all algebraic varieties

Types of variety :

• AffineVariety -- the class of all affine varieties
• ProjectiveVariety -- the class of all projective varieties

Functions and methods returning a variety :

• variety(CoherentSheaf) -- get the variety
• variety(SheafOfRings) -- get the variety

Methods that use a variety :

• ideal(Variety) -- returns the defining ideal
• "ring(Variety)" -- see ring -- get the associated ring of an object
• sheaf(Variety) -- make a coherent sheaf
• sheaf(Variety,Module) -- make a coherent sheaf
• sheaf(Variety,Ring) -- make a coherent sheaf of rings

For the programmer

The object Variety is a type, with ancestor classes MutableHashTable < HashTable < Thing.