WhatYouCanDoList

This is a quick list of things that is implemented in the latest version of QPA. For further information see the manual of QPA.

Now and then we compile a release of QPA, which you can download from this web page on SourceForge.net. The current version is 1.16.

Between the different releases, updates are made, and if you want to take advantage of these updates, you should make a copy or a clone of the GIT-repository at SourceForge.net. Give the command

git clone git://git.code.sf.net/p/quiverspathalg/qpa qpa

in the /gap/pkg/-directory to make a clone of the GIT-repository. See the more detailed instructions here how to do this.

If you have suggestions of computations that you want to see implemented and it is not on the list, please contact us.

Functors

Compute the dual of a moduleDone
Compute the dual of a map between two modulesDone
Compute a basis for Hom(M,N)Done
Compute the transpose of a moduleDone
Compute the transpose of the dualDone
Compute the dual of the transposeDone
Compute Hom(-,A): mod A ---> mod A^\opDone
Nakayama functor for selfinjective algebrasDone

Algebras

Check if an ideal is monomialDone
Check if an ideal is admissibleDone
Test for distributivity of an algebraDone
Tests for finite type of an algebraPartially Done
Compute the product of two idealsDone
Compute the opposite algebraDone
Compute the tensor product of two algebrasDone
Compute the enveloping an algebraDone
Compute the trivial extension of an algebraDone
Check if an algebra is distributive?Done
Check if an algebra is gentle?Done
Check if an algebra is selfinjectivePartially done
Check if an algebra is special biserialDone
Check if an algebra is a string algebraDone
Check if an algebra is a Schurian algebraDone
Check if an algebra symmetric?Done
Check if an algebra weakly symmetric?Done
Find the center of an algebraPartially Done
Find a minimal generating set of an admissible idealDone
Find the Loewy length of an algebraDone
Nakayama automorphism for selfinjective algebrasDone
Dynkin quivers (simply laced)Done
Canonical algebra, predefined classDone
Kronecker algebra, predefined classDone
Nakayama algebra, predefined classDone
Truncated path algebrasDone
Compute an estimate of the complexity of an algebraDone
Compute the dominant dimension of an algebraDone
Compute the Koszul dualDone
Compute the ring structure of Ext^*(M,M) for a module MPartially Done

Modules

Find the dimension vector of a moduleDone
Construct the direct sum of two representationsDone
Find the submodule of a module generated by a set of elementsDone
Find the intersection of two submodules of a moduleDone
Find the sum of two submodules of a moduleDone
Find the radical of a moduleDone
Find the socle of a moduleDone
Find the top of a moduleDone
Find a minimal set of generators a moduleDone
Find the radical series of a moduleDone
Find the socle series of a moduleDone
Find the Loewy length of a moduleDone
Find all indecomposable projective modules over an algebraDone
Find all indecomposable injective modules over an algebraDone
Find all simple modules over an algebraDone
Make the algebra a module over the enveloping algebraDone
Make the dual of the algebra a module over the enveloping algebraDone
Test if a module is simple.Done
Test if a module is semisimple.Done
Test if a module is projective.Done
Test if a module is injective.Done
Test if a module is Omega periodic.Done
Test if two modules are isomorphic.Done
Find an isomorphism between isomorphic modulesDone
Test if a module is a direct summand in another.Done
Find a common direct summand in two given modules.Done
Find the maximal common direct summand in two given modules.Done
Test if a module is in the additive closure of another module.Done
Test if a module as a finite resolution or coresolution in the additive closure of another module.Done
Test if a module is tilting/cotilting module.Done
Find the left and right mutation of an almost complete tilting/cotilting module.Done
Find the number of complements of an almost complete tilting/cotilting module.Done
Find all complements of an almost complete tilting/cotilting module given one complement.Done
Find the annihilator of a moduleDone
Find the basic version of a moduleDone (over finite fields)
Decomposition of modulesPartially Done (over finite fields)
Decomposition of modules with multiplicitiesPartially Done (over finite fields)
Block decomposition and blocksplitting idempotents of a moduleDone
Compute an estimate of the complexity of a moduleDone
Find a projective presentation of a module over the corresponding path algebraDone
Compute the almost split sequence ending in an indecomposable moduleDone
Compute the predecessor of an indecomposable module in the AR-quiverDone
Degeneration order for modules of (some) algebras of finite typeDone

Homomorphisms

Represent maps between representationsDone
Compute kernel, image and cokernel of a map between modulesDone
Compute the image and the preimage of an element for a map between modulesDone
Check if a map between modules is one-to-one, onto, isomorphism and zeroDone
Composition and addition of maps between representationsDone
Compute pushouts and pullbacksDone
Given a commutative diagram of homomorphisms of modules, compute the homomorphisms induced on kernels and cokernels.Done
Given an epimorphism g and a homomorphism f from a direct sum of indecomposable projective modules to the range of g, finds a lifting of f to the source of g.Done
Find the endomorphism ring of a moduleDone
Test if a map is split epi.Done
Test if a map is split mono.Done
Test if a map is left or right minimal.Done
Given a homomorphism between two modules, find the left and the right minimal version of this homomorphism.Done
Compute minimal left/right approximations of a module X with respect to another module MDone
Compute the trace of a module M in another module NDone
Compute Fac(M) and Sub(M) left/right approximations of modulesDone

Resolutions/homological algebra

Find the projective cover of a module.Done
Find the first syzygy of a module.Done (using linear algebra)
Find the n-th syzygy of a module.Done (using linear algebra)
Find the first extension group for two modules.Done
Find the injective and the projective dimension of a module.Done
Find the global dimension of an algebra.Done
Find the dominant dimension of a moduleDone
Find the faithful dimension of a moduleDone
Data structures for complexes of finitely generated modules and morphisms between suchDone
Truncations of complexes, splicing of complexes, acyclicity testDone
Mapping cones of morphisms of complexesDone
Check if a complex is a perfect complexDone
Check if a complex is a coperfect complexDone
Projective resolutions of bounded complexes of finitely generated modulesDone
Compute tau of a finite complex of projectivesDone
Find a Iyama generator for a moduleDone

Invariants

Cartan matrixDone
Coxeter transformationDone
Coxeter polynomialDone
Unit formsDone
Tits unit form of an algebraDone
Is a unit form weakly positiveDone
Is a unit form weakly non-negativeDone

Oyvind.Solberg (at) math ntnu no