The denotational semantics
of a simple language which
includes jumps are programmed in Pascal to give an interpreter.
By concentrating on the final state of a program the semantics are
directly coded in Pascal with only slight modification to the
semantics equations. The interpreter was produced as easily as
the formal definition of the language and makes a reference
implementation and development testbed. By using a widespread
metalanguage such as Pascal this definition can be widely
understood and executed.