Function subjectively_accepted 

pub fn subjectively_accepted<A>(
    vaf: &ValueBasedFramework<A>,
    arg: &A,
) -> Result<bool, Error>
where
    A: Clone + Eq + Hash + Ord + Debug,

Returns Ok(true) iff arg is accepted by some total ordering of the values mentioned in the framework.

Strategy: enumerate every permutation of the value set, build the corresponding total-order Audience, and check accepted_for. Returns true on the first acceptance; otherwise false.