Yuri Santos

Epistemic logic is usually employed to model two aspects of a situation: the factual and the epistemic aspects. Truth, however, is not always attainable, and in many cases we are forced to reason only with whatever information is available to us. In this paper, we will explore a four-valued epistemic logic designed to deal with these situations, where agents have only knowledge about the available information, which can be incomplete or conflicting, but not explicitly about facts. This layer of available information or evidence, which is the object of the agents’ knowledge, can be seen as a database. By adopting this sceptical posture in our semantics, we prepare the ground for logics where the notion of knowledge—or more appropriately, belief—is entirely based on evidence. The technical results include a set of reduction axioms for public announcements, correspondence proofs, and a complete tableau system. In summary, our contributions are twofold: on the one hand we present an intuition and possible application for many-valued modal logics, and on the other hand we develop a logic that models the dynamics of evidence in a simple and intuitively clear fashion.

RESUMO É cada vez mais sensível a grande profusão de distintas formas de narratividade biográfica na sociedade contemporânea. A partir do que apresentam pesquisas em diferentes campos dos estudos em linguagem, faz-se incontestável a heterogenericidade com que diversas formas de narração do eu em diferentes tons de autorreferência têm insurgido numa sociedade altamente midiatizada e globalizada. Nesse entrever, ancorados no edifício teórico da análise dialógica do discurso em confluência com estudos que se debruçam sobre as escritas de si, propomo-nos a discutir a ressignificação como ato característico do movimento de autorreferência constitutivo da autobiografia e de algumas outras formas de narrativas do eu. Dentre outras observações, destacamos, na construção discursiva de textos autorreferentes, como a autobiografia, um entrecruzamento entre sentidos, memórias e vivências em uma relação de ressignificação sob a luz do que o sujeito não só foi como agora é. ABSTRACT The great profusion of different forms of biographical narrativity in contemporary society is increasingly sensitive. From what is presented by studies in different fields of language studies, the heterogeneity with which diverse forms of narration of the self in different tones of self-reference have emerged in a highly mediatized and globalized society becomes indisputable. Therefore, anchored in the theoretical propositions of the dialogic analysis of discourse along with studies that focus on life writings, we discuss re-signification as a characteristic act of the movement of self-reference, constitutive of autobiographies and some other forms of narratives of the self. Among other observations, we highlight in the discursive construction of self-referential texts, such as autobiography, a cross-linking between senses, memories and life experiences in their relation of re-signification in the light of what the subject not only was, but is now.