Fix typo
Add a general linear solver
Use "numbered_symbols"
Add example to the documentation
Free variables can be specified by an external generator
More documentation for the linear solver
Tests for general linear solver
Fix python 3 test failure
An algorithm for computing indefinite sums of rational and quasi-rational summands
Add rational summation to default imports
Clean up imports
Make rational summation work with new monomial tools
Small clean up
Use much more robust linear solver
Remove obsolete debug print statements
Handle case if linear system has no solution
Fix preprocess step to fail for inadmissible summands
Remove the constant of summation if any
Fix broken tests
Better function names