Extracts the instances used in a prenex FOL Pi_1 expansion tree / Sigma_1 expansion sequent.
Each expansion tree is transformed into a list of instances of its shallow formula.
In contrast to ExpansionProof.deep, this function doesn't produce conjunctions of instances, but instead increases the
number of formulas in the antecedent/succedent.
Extracts the instances used in a prenex FOL Pi_1 expansion tree / Sigma_1 expansion sequent.
Each expansion tree is transformed into a list of instances of its shallow formula.
In contrast to ExpansionProof.deep, this function doesn't produce conjunctions of instances, but instead increases the number of formulas in the antecedent/succedent.