need

   1 Action::AddValue
   2         RemoveValue
   3         BindValue
   4         SetBoundValue
   5         AddBoundValue
   6         RemoveBoundValue
   7 ActionBuilder::BoundValue
   8 ? KnownFactSet
   9 ? KnownResolutionSet
  10 Predicate::Foreach
  11 Predicate::Findall
  12 Predicate::Forall
  13 Predicate::Rule
  14 Predicate::Not
  15 Step::SubSolve
  16 Solution
  17 Endjinn