coefficient() with composite variable
Say I have something like this:
var('a','b','c') test=b*a + c*a + 3*a + b + c
I can find that the coefficient of 'a' is (b+c+3) using:
However, I am interested in find the coefficient of $ab$ (which in this case would just be $1$). I tried
but it just returns zero. Is something like this possible?