English Dictionary: logic | by the DICT Development Group |
3 results for logic | |
From WordNet (r) 3.0 (2006) [wn]: | |
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From Webster's Revised Unabridged Dictionary (1913) [web1913]: | |
Logic \Log"ic\, n. [OE. logike, F. logique, L. logica, logice, Gr. logikh` (sc. te`chnh), fr. logiko`s belonging to speaking or reason, fr. lo`gos speech, reason, le`gein to say, speak. See {Legend}.] 1. The science or art of exact reasoning, or of pure and formal thought, or of the laws according to which the processes of pure thinking should be conducted; the science of the formation and application of general notions; the science of generalization, judgment, classification, reasoning, and systematic arrangement; correct reasoning. | |
From The Free On-line Dictionary of Computing (15Feb98) [foldoc]: | |
logic 1. mathematics that deals with the formal principles, methods and criteria of validity of {inference}, reasoning and {knowledge}. Logic is concerned with what is true and how we can know whether something is true. This involves the formalisation of logical arguments and {proof}s in terms of symbols representing {proposition}s and {logical connective}s. The meanings of these logical connectives are expressed by a set of rules which are assumed to be self-evident. {Boolean algebra} deals with the basic operations of truth values: AND, OR, NOT and combinations thereof. {Predicate logic} extends this with existential and universal {quantifier}s and symbols standing for {predicate}s which may depend on variables. The rules of {natural deduction} describe how we may proceed from valid premises to valid conclusions, where the premises and conclusions are expressions in {predicate logic}. Symbolic logic uses a {meta-language} concerned with truth, which may or may not have a corresponding expression in the world of objects called existance. In symbolic logic, arguments and {proof}s are made in terms of symbols representing {proposition}s and {logical connective}s. The meanings of these begin with a set of rules or {primitive}s which are assumed to be self-evident. Fortunately, even from vague primitives, functions can be defined with precise meaning. {Boolean logic} deals with the basic operations of {truth value}s: AND, OR, NOT and combinations thereof. {Predicate logic} extends this with {existential quantifier}s and {universal quantifier}s which introduce {bound variable}s ranging over {finite} sets; the {predicate} itself takes on only the values true and false. Deduction describes how we may proceed from valid {premise}s to valid conclusions, where these are expressions in {predicate logic}. Carnap used the phrase "rational reconstruction" to describe the logical analysis of thought. Thus logic is less concerned with how thought does proceed, which is considered the realm of psychology, and more with how it should proceed to discover truth. It is the touchstone of the results of thinking, but neither its regulator nor a motive for its practice. See also fuzzy logic, logic programming, arithmetic and logic unit, first-order logic, See also {Boolean logic}, {fuzzy logic}, {logic programming}, {first-order logic}, {logic bomb}, {combinatory logic}, {higher-order logic}, {intuitionistic logic}, {equational logic}, {modal logic}, {linear logic}, {paradox}. 2. See also {arithmetic and logic unit}, {asynchronous logic}, {TTL}. (1995-03-17) |