no no no.
integrate(1/(x-1),x) returns log (x-1)
which means that the anti-derivative is log(x-1) PLUS A CONSTANT.
integrate(-1/(1-x),x) returns log(1-x)
which means that the anti-derivative is log(1-x) PLUS ANOTHER CONSTANT.
That means
log(x-1)-log(1-x) is a constant. IT DOES NOT MEAN THAT IT IS ZERO.
%,logcontract
shows that maxima knows that, too. It returns log(-1). This is a constant.
Introducing abs() in this answer is done in order to get around the fact
that
students don't always know as much about complex numbers as Maxima.
RJF