Question: Problem with integration when computing power series sum

Hello
I have a problem with Maple. I would like to compute following sum using differentiation:

an:=x^(4*n-3)/(4*n-3)

This power series is convergent for x in (-1,1).

Sum(an,n=1..infinity);

diff(%,x);

s1:=value(%);

pf:=convert(s1,parfrac);

Now when integrating:

subs(x=t,pf);

int(%,t);

the result is: 1/2*arctan(t)-1/4*ln(t-1)+1/4*ln(t+1) .

The problem is that ln(t-1) is not defined for t in (-1,1). This is caused by integration of the equation:

-1/4/(t-1)

which is

-1/4*ln(t-1)

But if I would integrate the equation in the following form:

1/4*(1/(1-t))

then the result of int(%,t); is

-1/4*ln(1-t)

which is defined for t in (-1,1).

So how can I deal with this? How can I force Maple to use the form 1/4*(1/(1-t)) instead of  -1/4/(t-1) without having to rewrite it manually?

Thank you.

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