Two separation theorems for natural deduction.

Natural Deduction Environment for Matita

Matita is a proof assistant characterised by a rich, user extensible, output facility based on a widget for the rendering of MathML Presentation, and by the automatic handling of overloading by means of a flexible disambiguation mechanism. We show how to use these features to obtain a simple learning environment for natural deduction, without modifying the source code or Matita.

Natural Deduction for Hybrid Logic

In this paper we give a natural deduction formulation of hybrid logic. Our natural deduction system can be extended with additional inference rules corresponding to conditions on the accessibility relations expressed by so-called geometric theories. Thus, we give natural deduction systems in a uniform way for a wide class of hybrid logics which appears to be impossible in the context of ordinar...

Dynamic Deduction for Natural Language

Bidirectional Natural Deduction

The goal of this paper is to present a theorem prover able to perform both forward and backward reasoning supported by a well deened formal system. This system for bidirectional reasoning has been proved equivalent to Gentzen's classical system of propositional natural deduction. This paper, primarily aimed at developing a deeper theoretical understanding of bidirectional reasoning, provides ba...

Focused Natural Deduction

Natural deduction for intuitionistic linear logic is known to be full of non-deterministic choices. In order to control these choices, we combine ideas from intercalation and focusing to arrive at the calculus of focused natural deduction. The calculus is shown to be sound and complete with respect to first-order intuitionistic linear natural deduction and the backward linear focusing calculus.