Simple Data Structuring
Derek Coleman · 1978
A simple structured type can be formed by the set product† of two or more unstructured types. The result is known as a record type. A familiar example is the type complex number, which consists of all possible ordered pairs of real numbers. Thus $$ \begin{gathered} \hfill type\,complex=record \\ \hfill realpart: real \\ \hfill imagpart : real \\ \hfill end \\ \end{gathered} $$ or more briefly $$ \begin{gathered} \hfill type\,complex = record \\ \hfill realpart, imagpart:real \\ \hfill end \\ \end{gathered} $$ define complex numbers to be records with realpart and imagpart components, and each components is of type real.