The set of morphismes between ChowSchemes

AUTHORS:

  • Manfred Lehn (2013)
  • Christoph Sorger (2013)
class sage.schemes.chow.scheme_homset.ChowSchemeHomsetFactory

Bases: sage.structure.factory.UniqueFactory

Factory for SHom-sets of schemes.

create_key_and_extra_args(X, Y, category=None, base=None, check=True)

Create a key that uniquely determines the SHom-set.

INPUT:

  • X – a chowscheme. The domain of the morphisms.
  • Y – a chowscheme. The codomain of the morphisms.
  • category – a category for the SHom-sets (default: chowschemes
    over given base).
  • base – a chowscheme. The base chowscheme of domain and codomain.
  • check – boolean (default: True).
create_object(version, key, **extra_args)

Create a SchemeHomset_generic.

INPUT:

  • version – object version. Currently not used.
  • key – a key created by create_key_and_extra_args().
  • extra_args – a dictionary of extra keyword arguments.
class sage.schemes.chow.scheme_homset.ChowSchemeHomset_generic(X, Y, category=None, check=True, base=None)

Bases: sage.categories.homset.HomsetWithBase

The base class for SHom-sets of ChowSchemes.

INPUT:

  • X – a chowscheme. The domain of the SHom-set.
  • Y – a chowscheme. The codomain of the SHom-set.
  • category – a category (optional). The category of the
    SHom-set.
  • check – boolean (optional, default=``True``). Whether to
    check the defining data for consistency.
Element

alias of sage.schemes.chow.morphism.ChowSchemeMorphism

natural_map()

Return a natural map in the SHom space.

OUTPUT:

A ChowSchemeMorphism if there is a natural map from domain to codomain. Otherwise, a NotImplementedError is raised.

zero_element()

Backward compatibility alias for self.zero()

sage.schemes.chow.scheme_homset.is_ChowSchemeHomset(H)

Test whether H is a chowscheme SHom-set.