Concepts inOn the covering of left recursive grammars
Formal grammar
A formal grammar (sometimes simply called a grammar) is a set of formation rules for strings in a formal language. The rules describe how to form strings from the language's alphabet that are valid according to the language's syntax. A grammar does not describe the meaning of the strings or what can be done with them in whatever context—only their form. Formal language theory, the discipline which studies formal grammars and languages, is a branch of applied mathematics.
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Left recursion
In computer science, left recursion is a special case of recursion. In terms of context-free grammar, a non-terminal is left-recursive if the left-most symbol in any of ’s ‘alternatives’ either immediately (direct left-recursive) or through some other non-terminal definitions (indirect/hidden left-recursive) rewrites to again.
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Context-free grammar
In formal language theory, a context-free grammar (CFG) is a formal grammar in which every production rule is of the form V → w where V is a single nonterminal symbol, and w is a string of terminals and/or nonterminals (w can be empty). The languages generated by context-free grammars are known as the context-free languages.
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Grammar
In linguistics, grammar is the set of structural rules that govern the composition of clauses, phrases, and words in any given natural language. The term refers also to the study of such rules, and this field includes morphology, syntax, and phonology, often complemented by phonetics, semantics, and pragmatics. Linguists do not normally use the term to refer to orthographical rules, although usage books and style guides that call themselves grammars may also refer to spelling and punctuation.
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Validity
In logic, an argument is valid if and only if its conclusion is entailed by its premises, a formula is valid if and only if it is true under every interpretation, and an argument form (or schema) is valid if and only if every argument of that logical form is valid.
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Idea
An idea is a concept or mental impression. Very often, ideas are construed as representational images; i.e. images of some object. In other contexts, ideas are taken to be concepts, although abstract concepts do not necessarily appear as images. Many philosophers consider ideas to be a fundamental ontological category of being. The capacity to create and understand the meaning of ideas is considered to be an essential and defining feature of human beings.
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Algorithm
In mathematics and computer science, an algorithm Listen/ˈælɡərɪðəm/ (originating from al-Khwārizmī, the famous mathematician Muḥammad ibn Mūsā al-Khwārizmī) is a step-by-step procedure for calculations. Algorithms are used for calculation, data processing, and automated reasoning. More precisely, an algorithm is an effective method expressed as a finite list of well-defined instructions for calculating a function.
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