Alternative forms of propositional calculus for a given deduction theorem
نویسنده
چکیده
In a propositional calculus based on combinatory logic it is necessary to have a restriction on the deduction theorem for implication as otherwise Curry's paradox results (see [5]). In [1] and [2] we restricted the deduction theorem for implication as follows: where Δ is any sequence of obs and HX stands for "X is a proposition". Motivation for this deduction theorem was given in [2] using the following three valued tables (that for implication also appears in Kleene [6]). where N can stand for "neither J nor F" and Γ (negation) can be defined by CP(ΞHI), 1 A question that arises is: to what extent are the entries in the third column and the third row of the table for implication uniquely determined by DTP, modus ponens and the (fairly obvious) rule: H IhHI? 1. Here P stands for implication. EHI, which can be interpreted as stating that all propositions are provable, is taken as the "standard false" proposition. Given that SHI is assigned F the table for Γ follows from that for D. After part (iii) on page xx, below we assume for SHI: ZH\,HXhX.
منابع مشابه
Inducing Search Methods from Proofs
A methodology is introduced for the automatic generation of proof search strategies in automated deduction. Examples are given by the application of this methodology to generate proof search strategies for modal logic S5 and Intuitionistic Propositional Calculus. Experimental results are presented.
متن کاملPredicate Formal System based on 1-level Universal AND Operator and its Soundness
The aim of this paper is solving the predicate calculus formal system based on 1-level universal AND operator. Firstly, universal logic and propositional calculus formal deductive system (0 1] h UL∈ , are introduced. Secondly, a predicate calculus formal deductive system (0 1] h UL∈ , ∀ based on 1-level universal AND operator is built. Thirdly, the soundness theorem and deduction theorem of sys...
متن کاملNatural Deduction for First-Order Hybrid Logic
This is a companion paper to [6] where a natural deduction system for propositional hybrid logic is given. In the present paper we generalize the system to the first-order case. Our natural deduction system for first-order hybrid logic can be extended with additional inference rules corresponding to conditions on the accessibility relations and the quantifier domains expressed by so-called geom...
متن کاملOn the complexity of propositional logics with an involutive negation
Let C be the propositional calculus given by a standard SBL-algebra; C is obtained from C by adding an involutive negation, with axioms and deduction rules as in [4]. Then C is coNP-complete.
متن کاملPermutability of Proofs in Intuitionistic Sequent Calculi
We prove a folklore theorem, that two derivations in a cut-free sequent calculus for intuitionistic propositional logic (based on Kleene’s G3) are inter-permutable (using a set of basic “permutation reduction rules” derived from Kleene’s work in 1952) iff they determine the same natural deduction. The basic rules form a confluent and weakly normalising rewriting system. §
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Notre Dame Journal of Formal Logic
دوره 20 شماره
صفحات -
تاریخ انتشار 1979