#2739 `structures' is not empty on startup

[Sergey Litvinov]

Global variable `structures' is not empty.

Maxima branch_5_33_base_76_ge99672b http://maxima.sourceforge.net
using Lisp CLISP 2.49 (2010-07-07)
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) structures;
(%o1) [ef_data(exponent, reduction, primitive, cardinality, order, 
                                                             factors_of_order)]

I think it is populated here
https://sourceforge.net/p/maxima/code/ci/master/tree/src/numth.lisp#l1435

[Gunter Königsmann]

Definitively looked strange. Resolved this with Commit #3676097d2f1fc3344.