1. The study of principles of reasoning, especially of the structure of propositions as distinguished from their content, and of method and validity in deductive reasoning.
a. A system of reasoning: Aristotle's logic.
b. A mode of reasoning: By that logic, we should sell the company tomorrow.
c. The formal, guiding principles of a discipline, school, or science.
3. Valid reasoning: Your paper lacks the logic to prove your thesis.
4. The relationship between elements and between an element and the whole in a set of objects, individuals, principles, or events: There's a certain logic to the motion of rush-hour traffic.
a. The nonarithmetic operations performed by a computer, such as sorting, comparing, and matching, that involve yes-no decisions.
b. Computer circuitry.
c. Graphic representation of computer circuitry.
[Middle English, from Old French logique, from Latin logica, from Greek logikē (tekhnē), (art) of reasoning, logic, feminine of logikos, of reasoning, from logos, reason; see leg- in the Appendix of Indo-European roots.]
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