Amer Amikhteh; Lotfollah Nabavi
Abstract
The uninorm logic UL is a fuzzy, substructural and semi-relevant logic. The Gentzen-style system for UL is obtained by removing the contraction rules and weakening from the Gentzen-style system of Godel fuzzy logic. The UL lacks "excluded middle", "positive paradox" and "negative paradox". The truth ...
Read More
The uninorm logic UL is a fuzzy, substructural and semi-relevant logic. The Gentzen-style system for UL is obtained by removing the contraction rules and weakening from the Gentzen-style system of Godel fuzzy logic. The UL lacks "excluded middle", "positive paradox" and "negative paradox". The truth function of uninorm is a relevance weakening of the t-norm function. In this article, we introduce the new logic ULΔ. ULΔ is obtained by adding Δ to UL. ULΔ, an expansion of classical logic, is a normal semilinear modal logic; i.e. it is strongly sound and complete w.r.t. a linearly ordered algebra. And with the theorem of (p→q)∨Δ(q→p) it is distinguished from other standard systems of modal logic. Δφ is intuitively interpreted as "true that φ" or more precisely "classically true that φ". In this paper, we introduce the semi-classical logic ULΔ with four approaches, axiomatizations, hypersequent calculi, algebraic semantics and standard semantics. metatheorems we are considering include Delta deduction, strong soundness, strong standard completeness and definability of classical logic.
2. .
Mohsen Shabani Samghabadi; Lotfollah Nabavi; Seyyed Mohammad Ali Hodjati
Philosophy of Logic
Nima Ahmadi; Lotfollah Nabavi; Seyyed Mohammad Ali Hodjati
Volume 8, Issue 2 , Summer and Autumn 2017, , Pages 1-23
Abstract
Contextualism is the main opponent of minimalism. The debate between these two semantical approaches, stem in an old fashion dispute to determine the border between semantics and pragmatics. Contextualists claim that the sentences in the natural language are not truth-evaluable before being enriched ...
Read More
Contextualism is the main opponent of minimalism. The debate between these two semantical approaches, stem in an old fashion dispute to determine the border between semantics and pragmatics. Contextualists claim that the sentences in the natural language are not truth-evaluable before being enriched pragmatically. In contrast, in minimalists’ viewpoint, there is a minimal semantic content that provides the truth-evaluable meaning of sentences in a way that context of utterance has limited effects on it. This contrast is based on the way and extent to which context affects semantic content. In this paper, after introducing these two approaches, the main arguments of contextualists against minimalist are discussed, then we show that minimalistic semantics like Kaplan's LD with objective interpretation of context cannot present any proper model even for sentences containing first-person reference, and on the basis of a subjective interpretation of context, the indexical/non-indexical distinction is not clear and other expressions of natural languages can be indexical, in a broad sense.
Seied Mohammad Ali Hodjati; Homan Mohammad Ghorbanian; Lotfollah Nabavi; Arsalan Golfam
Volume 4, Issue 1 , Winter and Spring 2013, , Pages 44-64
Abstract
Many philosophers claim that semantic content of language is normative, which means that meaning of a term prescribes the pattern of use or determines which pattern of use can be described as ‘correct’. The most important arguments for normativity, made by Kripke, Boghossian and others, are ...
Read More
Many philosophers claim that semantic content of language is normative, which means that meaning of a term prescribes the pattern of use or determines which pattern of use can be described as ‘correct’. The most important arguments for normativity, made by Kripke, Boghossian and others, are based on the concepts of ‘regularities’, ‘correct uses’ and ‘possibility of semantic mistakes’. But some philosophers have scrutinized the slogan ‘meaning is normative’ and have found some flaws in pro arguments. There are good reasons to consider the normativity of meaning as a side effect of ‘being public ’; that is, meaning, as itself, is neutral to correct or incorrect uses, but the moral or social laws of society impose several norms on language.
Lotfollah Nabavi; Amirhossein Yaraghchi
Volume 3, Issue 2 , Summer and Autumn 2012, , Pages 83-103
Abstract
From the very beginning up to now the concept of existence has been one of the most controversial ones among the philosophers. Such discussions can be divided into two main parts. The first one refers to the ontological aspects of existence for which one is involved with two schools namely Possibilism ...
Read More
From the very beginning up to now the concept of existence has been one of the most controversial ones among the philosophers. Such discussions can be divided into two main parts. The first one refers to the ontological aspects of existence for which one is involved with two schools namely Possibilism and Actualism anyone of which tries to talk of the scope and limit of things within their own metaphysical principles. The second part includes the issues about existence as a predicate. For these discussions and because we want to consider existence as a first or a second order predicate, we can either talk about the possible existence or its counterpart i.e., the necessary existence of the things. The necessary existence is one of the formula which, in the simplest quantified modal logic of S5 and just like those formula such as BF and CBF, is provable and valid. Although talking of the validity of necessary existence things needs to provide a second degree concept of existence but discussing the validity of Barcan formula needs an existential commitment to the possible things which the possibilists believe are not among the existent things. Following Linsky and Zalta and for defending BF and NE formula, Timotty Williamson has excluded the validity issue of Barcan formula from the first part and he has transferred it to the second part. Thus using the modal properties he provides a new definition of possible things through which one can defend the validity of Barcan formula as well as the necessary existence of things without having any existential commitment to the possibilia. Afterwards, Williamson provides the conditions for talking of the logical existence for things by providing a second-order concept of existence in unrestricted quantification theory and in this way one can have a better understanding of necessary existence.
