Check if a characteristic function is superadditive

To check if a characteristic function is superadditive use coopgt.characteristic_function_properties.is_superadditive.

For example to check if the following characteristic function is superadditive:

\[\begin{split}v_1(C)=\begin{cases} 0,&\text{if }C=\emptyset\\ 6,&\text{if }C=\{1\}\\ 12,&\text{if }C=\{2\}\\ 42,&\text{if }C=\{3\}\\ 10,&\text{if }C=\{1,2\}\\ 42,&\text{if }C=\{1,3\}\\ 42,&\text{if }C=\{2,3\}\\ 42,&\text{if }C=\{1,2,3\}\\ \end{cases}\end{split}\]

First create the characteristic function:

>>> characteristic_function = {
...     (): 0,
...     (1,): 6,
...     (2,): 12,
...     (3,): 42,
...     (1, 2): 10,
...     (1, 3): 42,
...     (2, 3): 42,
...     (1, 2, 3): 42,
... }

Then:

>>> import coopgt.characteristic_function_properties
>>> coopgt.characteristic_function_properties.is_superadditive(
...     characteristic_function=characteristic_function
... )
False