Maxima さん,勘弁してください.

1と2は特別なのでしょうか?

k@k ~ $ rmaxima --init=
Maxima 5.39.0 http://maxima.sourceforge.net
using Lisp CMU Common Lisp 21b (21B Unicode)
Distributed under the GNU Public License. See the file COPYING.
Dedicated to the memory of William Schelter.
The function bug_report() provides bug reporting information.
(%i1) newcontext();facts();
(%o1)                             context2947
(%o2)                                 []
(%i3) apply(assume,[x > 0,equal(1,sqrt(x))]);
(%o3)                     [x > 0, equal(1, sqrt(x))]
(%i4) apply(assume, [equal(-1,-sqrt(x))]);
*A2 gc_alloc_new_region failed, nbytes=8.
 CMUCL has run out of dynamic heap space (512 MB).
  You can control heap size with the -dynamic-space-size commandline option.

Imminent dynamic space overflow has occurred:
Only a small amount of dynamic space is available now.
Please note that you will be returned to the Top-Level without
warning if you run out of space while debugging.

Maxima encountered a Lisp error:

 Heap (dynamic space) overflow

Automatically continuing.
To enable the Lisp debugger set *debugger-hook* to nil.
(%i5) 
Maxima encountered a Lisp error:

 Interrupted at #xF7FDB430.

Automatically continuing.
To enable the Lisp debugger set *debugger-hook* to nil.
(%i5) facts();
(%o5)                     [x > 0, equal(1, sqrt(x))]
(%i6) newcontext();facts();
(%o6)                            context178628
(%o7)                                 []
(%i8) apply(assume,[x > 0,equal(2,sqrt(x))]);
(%o8)                     [x > 0, equal(2, sqrt(x))]
(%i9) apply(assume, [equal(-2,-sqrt(x))]);
*A2 gc_alloc_new_region failed, nbytes=8.
 CMUCL has run out of dynamic heap space (512 MB).

 Returning to top-level.
*A2 gc_alloc_new_region failed, nbytes=8.
 CMUCL has run out of dynamic heap space (512 MB).

 Returning to top-level.
*A2 gc_alloc_new_region failed, nbytes=8.
 CMUCL has run out of dynamic heap space (512 MB).

 Returning to top-level.
rlwrap: warning: maxima killed by SIGTRAP.
rlwrap has not crashed, but for transparency,
it will now kill itself (without dumping core)with the same signal

Trace/breakpoint trap
k@k ~ $ rmaxima --init=
Maxima 5.39.0 http://maxima.sourceforge.net
using Lisp CMU Common Lisp 21b (21B Unicode)
Distributed under the GNU Public License. See the file COPYING.
Dedicated to the memory of William Schelter.
The function bug_report() provides bug reporting information.
(%i1) newcontext();facts();
(%o1)                             context2947
(%o2)                                 []
(%i3) apply(assume,[x > 0,equal(2,sqrt(x))]);
(%o3)                     [x > 0, equal(2, sqrt(x))]
(%i4) apply(assume, [equal(-2,-sqrt(x))]);

Maxima encountered a Lisp error:

 Interrupted at #x1006880B.

Automatically continuing.
To enable the Lisp debugger set *debugger-hook* to nil.
(%i5) facts();
(%o5)                     [x > 0, equal(2, sqrt(x))]
(%i6) newcontext();facts();
(%o6)                            context101642
(%o7)                                 []
(%i8) apply(assume,[x > 0,equal(3,sqrt(x))]);
(%o8)                     [x > 0, equal(3, sqrt(x))]
(%i9) apply(assume, [equal(-3,-sqrt(x))]);
(%o9)                             [redundant]
(%i10) facts();
(%o10)                    [x > 0, equal(3, sqrt(x))]
(%i11) newcontext();facts();
(%o11)                           context101663
(%o12)                                []
(%i13) apply(assume,[x > 0,equal(4,sqrt(x))]);
(%o13)                    [x > 0, equal(4, sqrt(x))]
(%i14) apply(assume, [equal(-4,-sqrt(x))]);
(%o14)                            [redundant]