Why is the program not running? Is there a logical or syntax problem?

[behi00]

C:\Users\behnam_moein\PycharmProjects\pythonProject\venv\Scripts\python.exe C:\Users\behnam_moein\PycharmProjects\pythonProject\main.py
File "C:\Users\behnam_moein\PycharmProjects\pythonProject\main.py", line 19
def rule(master):
^
IndentationError: unindent does not match any outer indentation level

Process finished with exit code 1

------------------------------------------------------------------------------------------------------
Above we have the errors resulting from the execution of the program.