15 relations: Clarence Irving Lewis, Deontic logic, Directed set, Epistemic modal logic, Equivalence relation, Logic, Modal logic, Modus ponens, Partially ordered set, Preorder, Provability logic, S5 (modal logic), Saul Kripke, Tautology (logic), Weak ordering.
Clarence Irving Lewis (April 12, 1883 – February 3, 1964), usually cited as C. I. Lewis, was an American academic philosopher and the founder of conceptual pragmatism.
Deontic logic is the field of philosophical logic that is concerned with obligation, permission, and related concepts.
In mathematics, a directed set (or a directed preorder or a filtered set) is a nonempty set A together with a reflexive and transitive binary relation ≤ (that is, a preorder), with the additional property that every pair of elements has an upper bound.
Epistemic modal logic is a subfield of modal logic that is concerned with reasoning about knowledge.
In mathematics, an equivalence relation is a binary relation that is reflexive, symmetric and transitive.
Logic (from the logikḗ), originally meaning "the word" or "what is spoken", but coming to mean "thought" or "reason", is a subject concerned with the most general laws of truth, and is now generally held to consist of the systematic study of the form of valid inference.
Modal logic is a type of formal logic primarily developed in the 1960s that extends classical propositional and predicate logic to include operators expressing modality.
In propositional logic, modus ponens (MP; also modus ponendo ponens (Latin for "mode that affirms by affirming") or implication elimination) is a rule of inference.
In mathematics, especially order theory, a partially ordered set (also poset) formalizes and generalizes the intuitive concept of an ordering, sequencing, or arrangement of the elements of a set.
In mathematics, especially in order theory, a preorder or quasiorder is a binary relation that is reflexive and transitive.
Provability logic is a modal logic, in which the box (or "necessity") operator is interpreted as 'it is provable that'.
In logic and philosophy, S5 is one of five systems of modal logic proposed by Clarence Irving Lewis and Cooper Harold Langford in their 1932 book Symbolic Logic.
Saul Aaron Kripke (born November 13, 1940) is an American philosopher and logician.
In logic, a tautology (from the Greek word ταυτολογία) is a formula or assertion that is true in every possible interpretation.
In mathematics, especially order theory, a weak ordering is a mathematical formalization of the intuitive notion of a ranking of a set, some of whose members may be tied with each other.