English Computing Dictionary
operational semantics
A set of rules specifying how the state of an actual
or hypothetical computer changes while executing a program.
The overall state is typically divided into a number of
components, e.g. {stack}, {heap}, {register}s etc. Each rule
specifies certain preconditions on the contents of some
components and their new contents after the application of the
It is similar in spirit to the notion of a {Turing machine},
in which actions are precisely described in a mathematical
Compuare {axiomatic semantics}, {denotational semantics}.