2 research outputs found
A Note on Fixed Points in Justification Logics and the Surprise Test Paradox
In this note we study the effect of adding fixed points to justification
logics. We introduce two extensions of justification logics: extensions by
fixed point (or diagonal) operators, and extensions by least fixed points. The
former is a justification version of Smory\`nski's Diagonalization Operator
Logic, and the latter is a justification version of Kozen's modal
-calculus. We also introduce fixed point extensions of Fitting's
quantified logic of proofs, and formalize the Knower Paradox and the Surprise
Test Paradox in these extensions. By interpreting a surprise statement as a
statement for which there is no justification, we give a solution to the
self-reference version of the Surprise Test Paradox in quantified logic of
proofs. We also give formalizations of the Surprise Test Paradox in timed modal
epistemic logics, and in G\"odel-L\"ob provability logic.Comment: 40 pages. In version 3, Mkrtychev models for QLP are adde
Formalizing common sense for scalable inconsistency-robust information integration using Direct Logic(TM) reasoning and the Actor Model
Because contemporary large software systems are pervasively inconsistent, it
is not safe to reason about them using classical logic. The goal of Direct
Logic is to be a minimal fix to classical mathematical logic that meets the
requirements of large-scale Internet applications (including sense making for
natural language) by addressing the following issues: inconsistency robustness,
contrapositive inference bug, and direct argumentation.
Direct Logic makes the following contributions over previous work:
* Direct Inference (no contrapositive bug for inference)
* Direct Argumentation (inference directly expressed)
* Inconsistency-robust deduction without artifices such as indices (labels)
on propositions or restrictions on reiteration
* Intuitive inferences hold including the following:
* Boolean Equivalences
* Reasoning by splitting for disjunctive cases
* Soundness
* Inconsistency-robust Proof by Contradiction
Since the global state model of computation (first formalized by Turing) is
inadequate to the needs of modern large-scale Internet applications the Actor
Model was developed to meet this need. Using, the Actor Model, this paper
proves that Logic Programming is not computationally universal in that there
are computations that cannot be implemented using logical inference.
Consequently the Logic Programming paradigm is strictly less general than the
Procedural Embedding of Knowledge paradigm.Comment: Corrected: all types are stric