Question about assume



Dear All,
I am again puzzled at the output I get from maxima, but I may be
misunderstanding something.
Consider the very simple code below

assume(A_par>0);
assume(B_par>0);
assume(n>1);
beta_par:A_par*(n^2-1)/((2*(n^2-1)+1)/sqrt(n^2-1)*log(n+sqrt(n^2-1))+B_par*n)/n/(6*%pi);
limit(beta_par,n, infinity);


When I run it this is what I get

(%i23) batch("friction.max");

batching #p/home/iselllo/temp/friction.max
(%i24)                         assume(A_par > 0)
(%o24)                            [redundant]
(%i25)                         assume(B_par > 0)
(%o25)                            [redundant]
(%i26)                           assume(n > 1)
(%o26)                              [n > 1]
                                              2
                                      A_par (n  - 1)
                     ------------------------------------------------
                                        2                 2
                               (1 + 2 (n  - 1)) log(sqrt(n  - 1) + n)
                     B_par n + --------------------------------------
                                                  2
                                            sqrt(n  - 1)
                     ------------------------------------------------
                                            n
(%i27)    beta_par : ------------------------------------------------
                                          6 %pi
                                        2
                                A_par (n  - 1)
(%o27)    ----------------------------------------------------------
                        2                     2
                   (2 (n  - 1) + 1) log(sqrt(n  - 1) + n)
          6 %pi n (-------------------------------------- + B_par n)
                                      2
                                sqrt(n  - 1)
(%i28)                   limit(beta_par, n, infinity)
Is  (n - 1) (n + 1)  positive, negative, or zero?

positive;
          2
Is  sqrt(n  - 1) + n  positive or negative?

positive;
Is  n - 1  positive, negative, or zero?

positive;
Maxima encountered a Lisp error:

 Error in $LIMIT [or a callee]: Bind stack overflow.

Automatically continuing.
To reenable the Lisp debugger set *debugger-hook* to nil.
(%o29)                           friction.max



First, I do not understand why I am asked if e.g. (n-1) is positive or
negative, having already assumed that n>1.
But the final message sounds Greek to me; I used the same expression
elsewhere and it is a perfectly reasonable function for n>=2.
Can anyone enlighten me here?
Many thanks

Lorenzo


-- 
Life is what happens to you while you're busy making other plans.