GNU Emacs Calc 2.02 Manual
4.11.2 Recursion Depth
Calc uses recursion in many of its calculations. Emacs Lisp keeps a
variable max-lisp-eval-depth which limits the amount of recursion
possible in an attempt to recover from program bugs. If a calculation
ever halts incorrectly with the message "Computation got stuck or
ran too long," use the M command (calc-more-recursion-depth)
to increase this limit. (Of course, this will not help if the
calculation really did get stuck due to some problem inside Calc.)
The limit is always increased (multiplied) by a factor of two. There
is also an I M (calc-less-recursion-depth) command which
decreases this limit by a factor of two, down to a minimum value of 200.
The default value is 1000.
These commands also double or halve max-specpdl-size, another
internal Lisp recursion limit. The minimum value for this limit is 600.
