Typesetting Symbols

If using a few APL symbols in an ordinary document is all you need, you can forget about the APL front end. Simply adding the option apl to your preferred L^ATEX document style (e.g. \documentstyle[12pt,apl]{article}) enables you to state in your paper, e.g.:

By combining the simple APL symbols and we obtain the compound symbol .

\begin{quotation}
By combining the simple \APL\ symbols
\APLcircle\ and \APLstar\ we obtain the
compound symbol \APLcirclestar.
\end{quotation}

In fact, you can typeset all simple and compound symbols of APL2, as we have defined macros for all of them. Tables and , respectively, show them together with their macro names.

IBM was the first company to implement APL  but it did not remain the only one. Companies such as I. P. Sharp and Dyadic Systems have produced their own versions of the language. These and other companies, however, introduced only a few symbols not found in APL2. We have added twenty additional symbols to the APL2 character set to support typesetting Dyalog APL, I–APL, Sharp APL, and APL.68000 (see Table ).

As you have probably guessed from the names in Tables , , and we stick to a naming convention in order to minimize name clashes with other macro packages and also help users remembering the macro names. All macro names start with the \APL prefix, followed by the name of the symbol used in the APL literature. The symbol names for APL2 characters are taken from [IBM 85]. For those characters (cf. Table ) which are not included in the IBM list we have invented consistent names. We always use symbol names, not the name of APL functions these symbols might represent. The name of a compound APL symbol is the concatenation of the names of the simple APL symbols it is created from.

Figure: The Atomic Vector of APL2

As can be seen in Figure  which shows the character set (the atomic vector ) of APL2, not all APL characters are fancy symbols, and the language uses ordinary alphanumeric characters as well. To allow for a clean interface between the APL front end and the L^ATEX part of our system, we decided to define macros for these characters as well. Their names are constructed as follows:

Each macro name starts with \APL.
For each letter we append the upper or lowercase letter, if the letter is underlined we prefix the letter with ``u''.
Capital letters: \APLA, ..., \APLZ.
Lowercase letters: \APLa, ..., \APLz.
Underlined capital letters: \APLuA, ..., \APLuZ.
Underlined lowercase letters: \APLua, ..., \APLuz.
For numbers we simply append their names: \APLzero, ..., \APLnine.

The tiny numbers in the atomic vector of Figure  correspond to positions for which no printable characters are defined by APL2. In case the APL front end encounters a nonprintable character, e.g. the one at position 20 in , it generates \APLmiss{20}. The definition of the L^ATEX macro \APLmiss determines the printed representation of this character (the default macro in our style just prints the corresponding number in style \tiny).

Let us close this section with one more example of typesetting APL symbols:

\APLquaddivide\APLA\ corresponds to
$A^{-1}$ in mathematical notation
and \APLcircleslope\APLA\ corresponds
to $A^{T}$.

displays as:

corresponds to A^-1 in mathematical notation and corresponds to A^T.