J is a dialect of APL, a formal imperative language.
Because it is imperative, a sentence in J may also be called
an instruction, and may be executed
to produce a result.
Because it is formal and unambiguous it can be executed
mechanically by a computer, and is therefore called
a programming language.
Because it shares the analytic properties of mathematical notation,
it is also called an analytic language.

APL originated in an attempt to provide consistent notation for
the teaching and analysis of topics related to the application of
computers, and developed through its use in a variety of topics,
and its implementation in computer systems

J is implemented in C (as detailed in
Hui [6]),
and is ported to a number of different host computer systems.
The effect of the specific host is minimal, and communication
with it is confined to the single foreign conjunction
detailed in Appendix A. See help files for other host
facilities such as Windows.

The Introduction in this book provides guidance to beginners.
References [7-9]
use J in the exposition of various
mathematical topics.