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In theoretical computer science a pointer machine is an "atomistic" ''abstract computational machine'' model akin to the Random access machine. Depending on the type, a pointer machine may be called a linking automaton, a KU-machine, an SMM, an atomistic LISP machine, a tree-pointer machine, etc. (cf Ben-Amram 1995). At least three major varieties exist in the literature—the Kolmogorov-Uspenskii model (KUM, KU-machine), the Knuth linking automaton, and the Schönhage Storage Modification Machine model (SMM). The SMM seems to be the most common. From its "read-only tape" (or equivalent) a pointer machine receives ''input'' -- bounded symbol-sequences ("words") made of at least two symbols e.g. -- and it writes ''output'' symbol-sequences on an output "write-only" tape (or equivalent). To transform a symbol-sequence (input word) to an output symbol-sequence the machine is equipped with a "program" -- a finite-state machine (memory and list of instructions). Via its state machine the program ''reads'' the input symbols, ''operates'' on its ''storage structure'' -- a collection of "nodes" (registers) interconnected by "edges" (pointers labelled with the symbols e.g. ), and ''writes'' symbols on the output tape. Pointer machines cannot do arithmetic. Computation proceeds only by reading input symbols, modifying and doing various tests on its storage structure—the pattern of nodes and pointers, and outputting symbols based on the tests. "Information" is in the storage ''structure''. == Types of "Pointer Machines" == Both Gurevich and Ben-Amram list a number of very similar "atomistic" models of "abstract machines"; Ben-Amram believes that the 6 "atomistic models" must be distinguished from "High-level" models. This article will discuss the following 3 atomistic models in particular: * Schönhage's Storage Modification Machines (SMM), * Kolmogorov-Uspenskii Machines (KUM or KU-Machines), * Knuth's "Linking Automaton" But Ben-Amram add more: * Atomistic Pure-LISP Machine (APLM) * Atomistic Full-LISP machine (AFLM), * General atomistic Pointer Machines, * Jone's I Language (two types) 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「pointer machine」の詳細全文を読む スポンサード リンク
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