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Implication Operation
Implication may refer to: Logic * Logical consequence (also entailment or logical implication), the relationship between statements that holds true when one logically "follows from" one or more others * Material conditional (also material consequence, or implication), a logical connective and binary truth function typically interpreted as "If ''p'', then ''q''" ** material implication (rule of inference), a logical rule of replacement ** Implicational propositional calculus, a version of classical propositional calculus which uses only the material conditional connective * Strict conditional or strict implication, a connective of modal logic that expresses necessity * '' modus ponens'', or Implication elimination, a simple argument form and rule of inference summarized as "''p'' implies ''q''; ''p'' is asserted to be true, so therefore ''q'' must be true" Linguistics * Implicature, what is suggested in an utterance, even though neither expressed nor strictly implied * Implic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Logical Consequence
Logical consequence (also entailment) is a fundamental concept in logic, which describes the relationship between statements that hold true when one statement logically ''follows from'' one or more statements. A valid logical argument is one in which the conclusion is entailed by the premises, because the conclusion is the consequence of the premises. The philosophical analysis of logical consequence involves the questions: In what sense does a conclusion follow from its premises? and What does it mean for a conclusion to be a consequence of premises?Beall, JC and Restall, Greg, Logical Consequence' The Stanford Encyclopedia of Philosophy (Fall 2009 Edition), Edward N. Zalta (ed.). All of philosophical logic is meant to provide accounts of the nature of logical consequence and the nature of logical truth. Logical consequence is necessary and formal, by way of examples that explain with formal proof and models of interpretation. A sentence is said to be a logical conse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Material Conditional
The material conditional (also known as material implication) is an operation commonly used in logic. When the conditional symbol \rightarrow is interpreted as material implication, a formula P \rightarrow Q is true unless P is true and Q is false. Material implication can also be characterized inferentially by modus ponens, modus tollens, conditional proof, and classical reductio ad absurdum. Material implication is used in all the basic systems of classical logic as well as some nonclassical logics. It is assumed as a model of correct conditional reasoning within mathematics and serves as the basis for commands in many programming languages. However, many logics replace material implication with other operators such as the strict conditional and the variably strict conditional. Due to the paradoxes of material implication and related problems, material implication is not generally considered a viable analysis of conditional sentences in natural language. Notation In l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Material Implication (rule Of Inference)
In propositional logic, material implication is a valid rule of replacement that allows for a conditional statement to be replaced by a disjunction in which the antecedent is negated. The rule states that ''P implies Q'' is logically equivalent to ''not-P or Q'' and that either form can replace the other in logical proofs. In other words, if P is true, then Q must also be true, while if Q is true, then P cannot be true either; additionally, when P is not true, Q may be either true or false. P \to Q \Leftrightarrow \neg P \lor Q Where "\Leftrightarrow" is a metalogical symbol representing "can be replaced in a proof with," and P and Q are any given logical statements. To illustrate this, consider the following statements: * P: Sam ate an orange for lunch * Q: Sam ate a fruit for lunch Then, to say, "Sam ate an orange for lunch" "Sam ate a fruit for lunch" (P \to Q). Logically, if Sam did not eat a fruit for lunch, then Sam also cannot have eaten an orange for lunch (b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Implicational Propositional Calculus
In mathematical logic, the implicational propositional calculus is a version of classical propositional calculus which uses only one connective, called implication or conditional. In formulas, this binary operation is indicated by "implies", "if ..., then ...", "→", "\rightarrow ", etc.. Functional (in)completeness Implication alone is not functionally complete as a logical operator because one cannot form all other two-valued truth functions from it. For example, the two-place truth function that always returns '' false'' is not definable from → and arbitrary sentence variables: any formula constructed from → and propositional variables must receive the value ''true'' when all of its variables are evaluated to true. It follows that is not functionally complete. However, if one adds a nullary connective ⊥ for falsity, then one can define all other truth functions. Formulas over the resulting set of connectives are called f-implicational. If ''P'' and ''Q'' are proposit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strict Conditional
In logic, a strict conditional (symbol: \Box, or ⥽) is a conditional governed by a modal operator, that is, a logical connective of modal logic. It is logically equivalent to the material conditional of classical logic, combined with the necessity operator from modal logic. For any two propositions ''p'' and ''q'', the formula ''p'' → ''q'' says that ''p'' materially implies ''q'' while \Box (p \rightarrow q) says that ''p'' strictly implies ''q''. Strict conditionals are the result of Clarence Irving Lewis's attempt to find a conditional for logic that can adequately express indicative conditionals in natural language. They have also been used in studying Molinist theology. Avoiding paradoxes The strict conditionals may avoid paradoxes of material implication. The following statement, for example, is not correctly formalized by material implication: : If Bill Gates has graduated in Medicine, then Elvis never died. This condition should clearly be false: the degree of Bill ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Modus Ponens
In propositional logic, ''modus ponens'' (; MP), also known as ''modus ponendo ponens'' (Latin for "method of putting by placing") or implication elimination or affirming the antecedent, is a deductive argument form and rule of inference. It can be summarized as "''P implies Q.'' ''P'' is true. Therefore ''Q'' must also be true." ''Modus ponens'' is closely related to another valid form of argument, ''modus tollens''. Both have apparently similar but invalid forms such as affirming the consequent, denying the antecedent, and evidence of absence. Constructive dilemma is the disjunctive version of ''modus ponens''. Hypothetical syllogism is closely related to ''modus ponens'' and sometimes thought of as "double ''modus ponens''." The history of ''modus ponens'' goes back to antiquity. The first to explicitly describe the argument form ''modus ponens'' was Theophrastus. It, along with ''modus tollens'', is one of the standard patterns of inference that can be applied to d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Implicature
In pragmatics, a subdiscipline of linguistics, an implicature is something the speaker suggests or implies with an utterance, even though it is not literally expressed. Implicatures can aid in communicating more efficiently than by explicitly saying everything we want to communicate. The philosopher H. P. Grice coined the term in 1975. Grice distinguished ''conversational'' implicatures, which arise because speakers are expected to respect general rules of conversation, and ''conventional'' ones, which are tied to certain words such as "but" or "therefore". Take for example the following exchange: : A (to passer by): I am out of gas. : B: There is a gas station 'round the corner. Here, B does not say, but ''conversationally implicates'', that the gas station is open, because otherwise his utterance would not be relevant in the context. Conversational implicatures are classically seen as contrasting with entailments: They are not necessary or logical consequences of what is said, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Implicational Universal
A linguistic universal is a pattern that occurs systematically across natural languages, potentially true for all of them. For example, ''All languages have nouns and verbs'', or ''If a language is spoken, it has consonants and vowels.'' Research in this area of linguistics is closely tied to the study of linguistic typology, and intends to reveal generalizations across languages, likely tied to cognition, perception, or other abilities of the mind. The field originates from discussions influenced by Noam Chomsky's proposal of a Universal Grammar, but was largely pioneered by the linguist Joseph Greenberg, who derived a set of forty-five basic universals, mostly dealing with syntax, from a study of some thirty languages. Though there has been significant research into linguistic universals, in more recent time some linguists, including Nicolas Evans and Stephen C. Levinson, have argued against the existence of absolute linguistic universals that are shared across all languages. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Implicational Hierarchy
Implicational hierarchy, in linguistics, is a chain of implicational universals. A set of chained universals is schematically shown as in (1): (1) A < B < C < D It can be reformulated in the following way: If a language has property D, then it also has properties A, B, and C; if a language has a property C, then it also has properties A and B, etc. In other words, the implicational hierarchy defines the possible combinations of properties A, B, C, and D as listed in matrix (2): Implicational hierarchies are a useful tool in capturing linguistic generalizations pertaining the different components of the language. They are found in all subfields of grammar. Phonology (3) is an example of an implicational hierarchy concerning the distribution of nasal phonemes across languages, which concerns dental/alveolar, bilabial, and palatal voiced nasals, respectively: (3) < < This hierarchy defines the following possible combinations of dental/alveola ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Entailment (pragmatics)
Linguistic entailments are entailments which arise in natural language. If a sentence ''A'' entails a sentence ''B'', sentence ''A'' cannot be true without ''B'' being true as well. For instance, the English sentence "Pat is a fluffy cat" entails the sentence "Pat is a cat" since one cannot be a fluffy cat without being a cat. On the other hand, this sentence does not entail "Pat chases mice" since it is possible (if unlikely) for a cat to not chase mice. Entailments arise from the semantics of linguistic expressions. Entailment contrasts with the pragmatic notion of implicature. While implicatures are fallible inferences, entailments are enforced by lexical meanings plus the laws of logic. Entailments also differ from presuppositions, whose truth is taken for granted. The classic example of a presupposition is the existence presupposition which arises from definite descriptions. For instance, the sentence "The king of France is bald" presupposes that there is a king of France. Unl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Implication Table
An implication table is a tool used to facilitate the minimization of states in a state machine. The concept is to start assuming that every state may be able to combine with every other state, then eliminate combinations that are not possible. When all the impossible combinations have been eliminated, the remaining state combinations are valid, and thus can be combined. The procedure is as follows: # List state-combination possibilities in an implication table, # Eliminate combinations that are impossible because the states produce different outputs, # Eliminate combinations that are impossible because the combination depends on the equivalence of a previously eliminated possibility, # Repeat the above step until no more eliminations are possible. References * Automata (computation) {{Formalmethods-stub hr:Minimizacija konačnog automata ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Implication Graph
In mathematical logic and graph theory, an implication graph is a skew-symmetric, directed graph composed of vertex set and directed edge set . Each vertex in represents the truth status of a Boolean literal, and each directed edge from vertex to vertex represents the material implication "If the literal is true then the literal is also true". Implication graphs were originally used for analyzing complex Boolean expressions. Applications A 2-satisfiability instance in conjunctive normal form can be transformed into an implication graph by replacing each of its disjunctions by a pair of implications. For example, the statement (x_0\lor x_1) can be rewritten as the pair (\neg x_0 \rightarrow x_1), (\neg x_1 \rightarrow x_0). An instance is satisfiable if and only if no literal and its negation belong to the same strongly connected component of its implication graph; this characterization can be used to solve 2-satisfiability instances in linear time. In CDCL SAT-solvers, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
