Hi,
take_match after factor_in behaves in a weird way. For example
ex := A W + B W + C;
factor_in(_, $A, B$);
take_match(_, $Q?? W$);
gives the result "C" rather than (A + B) W. If I do it the other way around, ie take_match first and then factor_in I get the expected result.
Best,
Andrei