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Working with Ext -- information about functorial properties
Hom and Ext
Ext^ZZ(Module,Module)
-- Ext module
Ext^ZZ(Matrix,Module)
-- map between Ext modules
Ext^ZZ(Module,Matrix)
-- map between Ext modules
Hom(Complex,Complex)
-- the complex of homomorphisms between two complexes
Hom(ComplexMap,ComplexMap)
-- the map of complexes between Hom complexes
homomorphism(ComplexMap)
-- get the homomorphism from an element of Hom
homomorphism'(ComplexMap)
-- get the element of Hom from a map of complexes
connectingExtMap(Module,Matrix,Matrix)
-- makes the connecting maps in Ext
Yoneda extensions and elements of Ext
yonedaMap(Matrix)
-- creates a chain complex map representing an extension of modules
yonedaMap'(ComplexMap)
-- identifies the element of Ext corresponding to a map of free resolutions
yonedaExtension(Matrix)
-- creates a chain complex representing an extension of modules
yonedaExtension'(Complex)
-- identifies the element of Ext corresponding to an extension
yonedaProduct(Matrix,Matrix)
-- make the product of two elements in Ext modules
yonedaProduct(Module,Module)
-- make the product map between Ext modules
See also
Making chain complexes
-- information about the basic constructors
Making maps between chain complexes
-- information about the basic constructors
Basic invariants and properties
-- information about accessing basic features
Working with Tor
-- information about functorial properties
Towards computing in the derived category