For instance, the sub-formula n 1 ≺ + n 2 , which states that node n 1 strictly precedes node n 2 , is translated into: where 15 EqDown x = Eq x Down x for x ∈ {n 1 , n 2 }.
in a valid minimal tree model, the set of nodes below or equal to n 1 is included in the set of nodes (strictly) on the left of n 2 , the set of nodes below or equal to n 2 is included in the set of nodes (strictly) on the right of n 1 , the set of nodes on the right of n 2 is included in the set of nodes on the right of n 1 , and finally the set of nodes on the left of n 1 is included in the set of nodes on the left of n 2 .