check_f: Check if the function is bijective
Description
This function checks if a given up or down action is bijective. This is done via checking that the order of the codomain is the same as the order of the domain of the function.
Usage
check_f(S_X, k, X_squared)
Arguments
S_X
All words of length 2 in a given set after up/down operation.
X_squared
All words of length 2 in a given set.