The program is a parser of mathematical expressions using the recursive descent method.
Added handling of the following errors in package exceptions:
-expression parsing error;
-expression errors.
All classes in package base and common, as well as tests, were developed by my teacher Korneev Georgy Alexandrovic.
To learn more about the capabilities of the parser, go to the https://www.kgeorgiy.info/courses/prog-intro/homeworks.html and read the conditions of 11-13 homework assignments.