Skip to main content

operational semantics

operational semantics An approach to the semantics of programming languages that uses the concept of an “abstract machine” that has a state and some primitive instructions or rules that cause the states to change. The machine is defined by specifying how the components of the state are changed by each of the instructions or rules. Computations are sequences of state transitions. The abstract machine is not meant to be a model of any realistic machine or machine language; it is meant to be simple enough so that the language can be unambiguously defined by simple rules for state transitions. The semantic description of a programming language specifies a translation into this operational model. Examples of this approach include the Vienna Definition Language used to define PL/I, which was the first method for defining the semantics of a programming language.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"operational semantics." A Dictionary of Computing. . 14 Mar. 2019 <>.

"operational semantics." A Dictionary of Computing. . (March 14, 2019).

"operational semantics." A Dictionary of Computing. . Retrieved March 14, 2019 from

Learn more about citation styles

Citation styles gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, cannot guarantee each citation it generates. Therefore, it’s best to use citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

The Chicago Manual of Style

American Psychological Association

  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.