bug check 2103

[GinoGiotto]

File that generates the bug:

ax1 $a A $.

th1 $p A $= ax1 $.

Metamath-exe interface:

Metamath - Version 0.199.pre 29-Jan-2022      Type HELP for help, EXIT to exit.
MM> set scroll continuous
Continuous scrolling is now in effect.
MM> read issue169.mm /verify
Reading source file "issue169.mm"... 32 bytes
32 bytes were read into the source buffer.
The source has 2 statements; 1 are $a and 1 are $p.

?Error on line 1 of file "issue169.mm" at statement 1, label "ax1", type "$a":
ax1 $a A $.
       ^
This math symbol was not declared (with a "$c" or "$v" statement).

?Error on line 1 of file "issue169.mm" at statement 1, label "ax1", type "$a":
ax1 $a A $.
       ^
The first symbol must be a constant in a "$a" statement.

?Error on line 1 of file "issue169.mm" at statement 1, label "ax1", type "$a":
ax1 $a A $.
       ^
This variable does not occur in any active "$e" or "$f" hypothesis.  All
variables in "$a" and "$p" statements must appear in at least one such
hypothesis.
SET EMPTY_SUBSTITUTION was turned ON (allowed) for this database.

?Error on line 1 of file "issue169.mm" at statement 1, label "ax1", type "$a":
ax1 $a A $.
The variable "A" does not appear in an active "$f" statement.

?Error on line 3 of file "issue169.mm" at statement 2, label "th1", type "$p":
th1 $p A $= ax1 $.
       ^
This math symbol was not declared (with a "$c" or "$v" statement).

?Error on line 3 of file "issue169.mm" at statement 2, label "th1", type "$p":
th1 $p A $= ax1 $.
       ^
The first symbol must be a constant in a "$p" statement.

?Error on line 3 of file "issue169.mm" at statement 2, label "th1", type "$p":
th1 $p A $= ax1 $.
       ^
This variable does not occur in any active "$e" or "$f" hypothesis.  All
variables in "$a" and "$p" statements must appear in at least one such
hypothesis.

?Error on line 3 of file "issue169.mm" at statement 2, label "th1", type "$p":
th1 $p A $= ax1 $.
The variable "A" does not appear in an active "$f" statement.
0 10%  20%  30%  40%  50%  60%  70%  80%  90% 100%
..................................................?BUG CHECK:  *** DETECTED BUG 2103

To get technical support, please open an issue
(https://github.com/metamath/metamath-exe/issues) with the
detailed command sequence or a command file that reproduces this bug,
along with the source file that was used.  See HELP OPEN LOG for help on
recording a session.  See HELP SUBMIT for help on command files.  Search
for "bug(2103)" in the m*.c source code to find its origin.
If earlier errors were reported, try fixing them first, because they
may occasionally lead to false bug detection

Press S  to step to next bug, I  to ignore further bugs,
or A  to abort program:  S

Warning!!!  A bug was detected, but you are continuing anyway.
The program may be corrupted, so you are proceeding at your own risk.



8 errors were found.
MM>

Without the /VERIFY option the bug does not occur (the verify proof * command triggers the bug as well).