ChangeMatrix -- an optional argument

Functions with optional argument named ChangeMatrix:

• forceGB(...,ChangeMatrix=>...) -- specify the change of basis matrix from a Gröbner basis to the generators of a module
• gb(...,ChangeMatrix=>...) -- see gb -- compute a Gröbner basis
• markedGB(...,ChangeMatrix=>...) -- see markedGB(Matrix,Matrix) -- make a marked Gröbner basis
• smithNormalForm(...,ChangeMatrix=>...) -- see smithNormalForm(Matrix) -- smith normal form for a matrix over a PID