Probably many bugs.

Knowns bugs:

* The overflows/underflows are not yet implemented in all functions.

* Possible integer overflows on some machines.

* get_str.c: condition len != n + 1 is always satisfied at the end.
  This means that there are too many reallocations (possibly useless
  ones) and a possible bug.

* TMP_ALLOC problems in agm.c and sqrt.c. (Kevin Ryde, 05 March 2002)

* mpfr_log10 seems to go into an infininite loop on certain inputs, for
  instance log10(10). (Kevin Ryde, 12 Mar 2002)

* tan(3*pi/4) gives ~ +1 instead of ~ -1. (Kevin Ryde, 12 Mar 2002)