Mario R. F. Benevides. Differentiating Assumptions from Extra-Logical Axioms in Natural Deduction. In Georg Gottlob, Alexander Leitsch, Daniele Mundici, editors, Computational Logic and Proof Theory, Third Kurt Gödel Colloquium, KGC 93, Brno, Czech Republic, August 24-27, 1993, Proceedings. Volume 713 of Lecture Notes in Computer Science, pages 120-131, Springer, 1993.
Abstract is missing.