The set of morphismes between ChowSchemes¶
AUTHORS:
- Manfred Lehn (2013)
- Christoph Sorger (2013)
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class
sage.schemes.chow.scheme_homset.
ChowSchemeHomsetFactory
¶ Bases:
sage.structure.factory.UniqueFactory
Factory for SHom-sets of schemes.
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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
).
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create_object
(version, key, **extra_args)¶ Create a
SchemeHomset_generic
.INPUT:
version
– object version. Currently not used.key
– a key created bycreate_key_and_extra_args()
.extra_args
– a dictionary of extra keyword arguments.
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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.
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Element
¶
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natural_map
()¶ Return a natural map in the SHom space.
OUTPUT:
A
ChowSchemeMorphism
if there is a natural map from domain to codomain. Otherwise, aNotImplementedError
is raised.
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zero_element
()¶ Backward compatibility alias for self.zero()
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sage.schemes.chow.scheme_homset.
is_ChowSchemeHomset
(H)¶ Test whether
H
is a chowscheme SHom-set.