logic_utils module¶

Python infrastructure for the Mathematical Logic through Programming book.

@logic_utils.frozen(cls)¶

A class decorator that disallows assignment to instance variables after construction.

Parameters: cls (Type[~T]) – class to modify.
Return type: Type[~T]
Returns: The given class, modified so that assignment to instance variable is disallowed after construction.

class logic_utils.frozendict(*args, **kwargs)¶

An immutable variant of the built-in dict class.

@logic_utils.memoized_parameterless_method(method)¶

A method decorator for parameterless methods of immutable classes that memoizes the return value to avoid recalculation.

Parameters: method (Callable[[~T], ~S]) – method to modify.
Return type: Callable[[~T], ~S]
Returns: The given method, modified so that after its first execution, its functionality is replaced with simply returning the value calculated by its first execution. If the value calculated by the given method has a copy() method, then instead of returning this value, each execution of the returned method, including the first one, makes a fresh call to this copy() method and returns the result.

logic_utils.fresh_variable_name_generator¶: A generator for fresh variable names. The first call to next(fresh_variable_name_generator) will return 'z1', the second call to next(fresh_variable_name_generator) will return 'z2', and so on.

logic_utils.fresh_constant_name_generator¶: A generator for fresh constant names. The first call to next(fresh_constant_name_generator) will return 'e1', the second call to next(fresh_constant_name_generator) will return 'e2', and so on.

logic_utils.is_z_and_number(string)¶

Checks if the given string is z followed by a number.

Parameters: string (str) – string to check.
Return type: bool
Returns: True if the given string is z followed by a number, False otherwise.