Workflow Satisfiability Problem is an important problem in access control, a field in information security. It is about setting up a workflow in an organisation in such a way that certain security$-$related constraints are satisfied. You are given a set of employees, or users, and a set of tasks $($e$.$g$.,$ a task could be to check a contract, or to sign it$,$ or to send it to the client$).$ The problem is to find an assignment of users to tasks such that all the constraints are satisfied. $($Note that every task has to be assigned to exactly one user; a user may be assigned one or several tasks, or may not be assigned any tasks.$)$ The constraints can be of the following types: $$ Authorisations: a user can only be assigned tasks that they are authorised for; for example, an employee may not be qualified to check a contract, in which case we can use the authorisations constraint to forbid the user