An unrestricted grammar is a formal grammar, where is a set of nonterminal symbols, is a set of terminal symbols, and are disjoint (actually, this is not strictly necessary, because unrestricted grammars make no real distinction between nonterminal and terminal symbols, the designation exists purely so that one knows when to stop when trying to generate sentential forms of the grammar), is a set of production rules of the form where and are strings of symbols in and is not the empty string, and is a specially designated start symbol. As the name implies, there are no real restrictions on the types of production rules that unrestricted grammars can have.
Read more about Unrestricted Grammar: Unrestricted Grammars and Turing Machines, Computational Properties
Famous quotes containing the words unrestricted and/or grammar:
“The words of the Constitution ... are so unrestricted by their intrinsic meaning or by their history or by tradition or by prior decisions that they leave the individual Justice free, if indeed they do not compel him, to gather meaning not from reading the Constitution but from reading life.”
—Felix Frankfurter (1882–1965)
“The syntactic component of a grammar must specify, for each sentence, a deep structure that determines its semantic interpretation and a surface structure that determines its phonetic interpretation.”
—Noam Chomsky (b. 1928)