This is the degree of the Homology group, that is, if one wants to calculate $H^D_3$, then degree=3.
k
This describes the order of the underlying rack or birack.
return_values
If return_values = TRUE, the functions returns the diagonal of the Smith Normal Form. If FALSE (the default), the function calls output_results instead which prints the homology group to the screen.
Value
NULL if return_values is FALSE, the diagonal of the Smith Normal Form if return_values is TRUE.
Details
This function is based on the algorithm described in the references below. It should be sufficient for most users to change the up/down action functions according to their requirements and then run the calculation.