Proof-graphs: a Thorough Cycle Treatment, Normalization and Subformula Property
Gleifer Vaz Alves, Anjolina Grisi de Oliveira, Ruy de Queiroz · Fundamenta Informaticae · 2011
A normalization procedure is presented for a classical natural deduction (ND) proof system. This proof system, called N-Graphs, has a multiple conclusion proof structure, where cycles are allowed. With this, we have developed a thorough treatment of