How statement and proof provenance work
The first chip identifies the source of the statement or construction; the second identifies the source of its local proof or verification.
- Literature-sourced: the exact statement appears in a cited source; only wording and notation differ.
- AI-adapted: a semantically identical restatement of literature-sourced material, modulo indexing, notation, and boundary cases adopted by the library.
- AI-generated: a genuinely novel statement formulated by AI, with no source for the claim itself.
These labels describe origin, not correctness: citations and verification chips remain separate evidence.
Languages over an alphabet
Definition
Let be an alphabet. A language over is a subset , where is the set of finite words of Computation alphabets, words, the empty word, and and is the subset relation of Subset , proper subset , and the separation notation .
Thus a language is a set of words over a fixed alphabet, not a set of alphabet symbols.
Remarks
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The ambient alphabet matters. The same set of written strings can be viewed as a language over different alphabets only when it is contained in each corresponding .
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The two extreme languages over are and .
Depends on
Used by
- The language {01} is not a set of alphabet symbols Counterexample
- Acceptance of a word by a DFA and the recognized language Definition
- Acceptance of a word by an NFA and the recognized language Definition
- Boolean operations on languages over a fixed alphabet Definition
- Computably enumerable sets and languages Definition
- Decision problems, search problems, and function problems Definition
- Epsilon-NFAs, finite epsilon closure, and extended word transition Definition
- Generalized NFA's and their accepted languages Definition
- Language concatenation, powers, and Kleene star Definition
- Languages recognized and decided by a Turing machine Definition
- Membership, emptiness, finiteness, equivalence, and containment for regular languages Definition
- Nerode equivalence of words Definition
- The language denoted by a regular expression Definition
- Word reversal and language reversal Definition
- FALSE: a language is a set of symbols False statement
- Every finite language is regular Proposition
Dependency tree · two levels
8 results within two dependency steps of this one, each drawn at its shortest distance from it. An arrow runs from a result to what uses it, so the chart reads left to right and ends at this result, which carries a heavier outline. Every node is a link to that result. Click elsewhere on the chart to enlarge it.
Sources
- Jean Gallier and Jocelyn Quaintance, Introduction to the Theory of Computation: Some Notes for CIS511 (standard reference, not scraped)
- John E. Savage, Models of Computation: Exploring the Power of Computing (standard reference, not scraped)
- Michael Sipser, MIT 18.404J Theory of Computation, Lecture 1 (standard reference, not scraped)