A Completeness Theorem in Modal Logic
A Critical Exposition of the Philosophy of Leibniz
A New Introduction to Modal Logic
A Solution of the Decision Problem for the Lewis systems S2 and S4, with an Application to Topology
A Survey of Symbolic Logic
A reduction in number of the postulates for C. I. Lewis' system of strict implication
Abelian Group
Absorption
Absorption law
Abstract algebra
Acta Philosophica Fennica
Adjunction
Admissible rule
Aegean
Affirming the consequent
Afshin Pouria
Alan Ross Anderson
Alan Turing
Alexius Meinong
Alfred North Whitehead
Alfred Tarski
Algebra
Algebraic structure
Algorithms
An Interpretation of the Intuitionistic Propositional Calculus
An Introduction to Modal Logic
An Introduction to Non-Classical Logic
Anaximander
Anaximenes
Angela
Anita Wasilewska
Apache
Apache Kafka
Apeiron
Apple
Archimedes
Arend Heyting
Aristotelian
Aristotle
Aristotle's Notion of Existence
Aristotle’s Logic
Arthur Conan Doyle
Arthur Norman Prior
Artificial intelligence
Asadollah Fallahi
Augustus De Morgan
Australia
Austria
Avicenna
Axiom KP
Axiom of Empty set
Axiom of Extensionality
Axiom of Foundation
Axiom of Replacement
Axiom of choice
Axiom of infinity
Axiom of pairing
Axiom of the power set
Axiom of the union
Axiom schema of separation
Mohammad ibn Musa al-Khwarizmi
S1
S2
Set theory
a priori
a prioricity
absolute
absurd
actualism
admin
aestheticism
affirm
affixing relevant logics
agnosticism
alethic
alligator
ambiguousness
anti-foundationalism
anti-haecceitism
anti-realism
anti-semitism
anti-verificationism
antihaecceitism
antisymmetric
apodictic
apophantic
approach
arithmetisation
arsenal
assertion
assertoric
associativity
assumptions
asymmetric
atomism
austerely
author
automaton
axiology
axiomatization
azure
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