Algorithms for processing text information, what to read?

Question

Programming

I decided to write my first bicycle in Python - a stubby analogue of Wolfram Alpha. The initial range of tasks - simple arithmetic calculations, the calculation of the root, the degree of a number, possibly a system of linear equations, but then develop. A text string is given as input to the program, processed using regular expressions, and depending on its syntax, the result is returned.
The question is that the program could process an incorrectly entered string and either select the appropriate option automatically, or give out a list of options ("Perhaps you meant ..."). As far as I understand, such an algorithm is similar to the Internet search algorithm (correct me if I misunderstood).
Where can you find information on this subject?

Answer 1

Reverse Polish Calculator: here

Answer 2

If I understand the question correctly, this topic is called Symbolic Computing . The topic is broad. Enough work for a long time.
In addition to parsing formulas, you will need to perform symbolic calculations.
Literature I can not advise, but links - please:
Algorithm for simplifying mathematical expressions
Symbolic calculations