Trying to use wxMaxima CAS v 19.03.1 for solving mathematical problems get
unsuccessful because of found errors. Because of this I can not run old already
saved past wxMaxima scripts with mathematical solutions. All such solutions
scripts worked well in past and are known as right mathematical solutions
without troubles when used.
Same behaviour is found also by interactive work with current version of
wxMaxima.

The reason for this problem was found in a incorrect behaviour where current
version of wxMaxima can not correctly assign values on Cyrillic words for
variables longer than 1 letter. When Cyrillic variables consisting just one
Cyrillic letter will be used to get some value this works fine.
Maxima which frontend is wxMaxima in the same computer works from CLI without
any troubles with Cyrillic variables much longer than 1 letter.
Based on above explanation I believe wxMaxima in openSUSE Leap 15.1 has a bug
and hopefully it could be fixed easily.