Difference between revisions of "Turing machine"

Revision as of 06:08, 16 February 2016

A Turing machine is a hypothetical device that manipulates symbols on a strip of tape according to a table of rules.

Description

Despite its simplicity, a Turing machine can be adapted to simulate the logic of any computer algorithm.

At a very high level, the machine consists of a memory tape divided into cells.

A "head" (e.g. a pencil/eraser) traverses the memory one cell at a time, writing or erasing data (e.g. numerical digits) based on user-specified rules.

The "machine" was invented in 1936 by Alan Turing who called it an "a-machine" (automatic machine).

The Turing machine is not intended as practical computing technology, but rather as a hypothetical device representing a computing machine.

Turing machines help computer scientists understand the limits of mechanical computation.

Turing completeness is the ability for a system of instructions to simulate a Turing machine.

Programming languages

A programming language that is Turing complete is theoretically capable of expressing all tasks accomplishable by computers.

Nearly all non-markup programming languages are Turing complete.

See also

• Church, Alonzo
• Computer science
• Entscheidungsproblem
• Lambda calculus
• Programming language
• Theoretical computer science
• Turing, Alan
• Turing completeness
• Universal Turing machine

External links

• Turing machine @ Wikipedia