Arbitrary Precision Arithmetic Package for Common Lisp

[Robert S. Boyer <boyer@CLI.COM>]

I suspect that the problem being reported with (expt 2 40000) is one
of printing it, not with constructing it.  I found it necessary to
increase the stacks, e.g., (setq si::*multiply-stacks* 4), to print
(expt 2 40000) in AKCL 1-615 on a Sun-3.  Here are some relevant
entries in AKCL 1-615 doc/DOC.

   *MULTIPLY-STACKS*
   Variable in SI package:

   If this variable is set to a positive fixnum, then the next time through the
   TOP-LEVEL loop, the loop will be exited.  The size of the stacks will be
   multiplied by the value of *multiply-stacks*, and the TOP-LEVEL will be called
   again.  Thus to double the size of the stacks:

   >(setq si::*multiply-stacks* 2)
   [exits top level and reinvokes it, with the new stacks in place]
   >

   We must exit TOP-LEVEL, because it and any other lisp functions
   maintain many pointers into the stacks, which would be incorrect when the
   stacks have been moved.    Interrupting the process of growing the stacks,
   can leave you in an inconsistent state.

   MULTIPLY-BIGNUM-STACK
   Function in the SI package:
   Args: (n)
   Increase the internal bignum stack by a factor of N.  Normally space on this
   stack is recovered after each complete lisp expression is evaluated.  However
   if you are dealing with large integers, you may need to use this function 
   to increase the stack.