ConcurrentRestrictions

Internal state type used to describe a set of tasks.

Updates the description g to include a new task a.

Representation of zero tasks.

Updates the description g to remove a previously added task a.

Returns true if the tasks described by g are allowed to execute concurrently. The methods in this class must obey the following laws:

1. forall g: G, a: A; valid(g) => valid(remove(g,a)) 2. forall a: A; valid(add(empty, a)) 3. forall g: G, a: A; valid(g) <=> valid(remove(add(g, a), a)) 4. (implied by 1,2,3) valid(empty) 5. forall g: G, a: A, b: A; !valid(add(g,a)) => !valid(add(add(g,b), a))