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In logic, specifically in deductive reasoning, an argument is valid if and only if it takes a form that makes it impossible for the premises to be true and the conclusion nevertheless to be false. It is not required for a valid argument to have premises that are actually true, but to have premises that, if they were … 展开
A statement can be called valid, i.e. logical truth, in some systems of logic like in Modal logic if the statement is true in all interpretations. In Aristotelian logic statements are not valid … 展开
In truth-preserving validity, the interpretation under which all variables are assigned a truth value of 'true' produces a truth value of 'true'. 展开
A formula of a formal language is a valid formula if and only if it is true under every possible interpretation of the language. In propositional logic, they are tautologies. 展开
Validity of deduction is not affected by the truth of the premise or the truth of the conclusion. The following deduction is perfectly valid: 展开
Model theory analyzes formulae with respect to particular classes of interpretation in suitable mathematical structures. On this reading, a formula is valid if all such interpretations make it true. An inference is valid if all interpretations that validate the … 展开
CC-BY-SA 许可证中的维基百科文本 Validity | Reasoning, Argument, Evidence | Britannica
网页validity, In logic, the property of an argument consisting in the fact that the truth of the premises logically guarantees the truth of the conclusion. Whenever the premises are …
Validity and Soundness - Internet Encyclopedia of Philosophy
网页Validity and Soundness. A deductive argument is said to be valid if and only if it takes a form that makes it impossible for the premises to be true and the conclusion nevertheless …
Introduction to Logic - Chapter 3 - Stanford University
网页We begin this chapter with a look at logical properties of individual sentences (as opposed to relationships among sentences) - validity, contingency, and unsatisfiability. We then …
Definition and Examples of Valid Arguments - ThoughtCo
- "The primary tool in deductive reasoningis the syllogism, a three-part argument consisting of two premises and a conclusion: The syllogism is a tool for analyzing the validity of an argument. You'll rarely find a formal syllogism outside of textbooks on logic. Mostly, you'll find enthymemes, abbreviated syllogisms with one or more of the parts unst...
- 发布日期: 2009年12月3日
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3.2.3: Validity in Predicate Logic - Humanities LibreTexts
网页A predicate logic argument is Valid if and only if it has no counterexamples. Let's illustrate the idea of counterexamples in examining the validity of Lae
Validity - logic.stanford.edu
网页A sentence is valid if and only if it is satisfied by every truth assignment. For example, the sentence ( p ∨ ¬ p ) is valid. A good method for determining the validity of a sentence is …
Validity and Satisfiability in Predicate Logic - University of Texas at ...
网页A predicate logic sentence w is valid if it is true in all interpretations. In other words, it is true regardless of what the constant, function, and predicate symbols “mean”. A …
Validity, Logical - SpringerLink
网页Logical validity refers to the evaluation of the soundness of an argument (i.e., how well it preserves the truth) (Michalos, 2006). Description An argument consists of a series of …
1.6: Validity - Humanities LibreTexts
网页2021年3月10日 · The central concept that you will learn in logic is the concept of validity. Validity relates to how well the premises support the conclusion, and it is the golden …
