"Yes, working with the XSD specification is a nightmare; it's the toughest spec I've ever had to work with other than Algol 68, and unlike Algol 68, some of the apparent formality turns out to be spurious; when it gets to tricky things that ought to be formal, like whether two types are identical, the spec bails out."
-- Michael Kay
"Since ALGOL 68 is a highly recursively structured language, it is quite impossible to describe it until it has been described. So that you can read this Introduction without tying your own mental processes into a recursive knot,
it has been laid out to a certain pattern, which we ask you to follow. Please,
therefore, start by reading once or twice "Very Informal Introduction", in
which we try to give a broad survey of what is in this language - mainly by
the way of small examples and plain explanations." -- Lindsey and v/d Meulen, "An Informal Introduction to Algol 68."
After chapter 0, the "Very Informal Introduction", you have a table of contents in the form of a grid. There are 8 following chapters on basic concepts, declarations, blocks, functions, expressions, operators, I/O, and examples, each of which is divided into as many as 7 subchapters (some grid cells are empty) on fundamentals, procedures and pointers, operations, structures, arrays, unions, and miscellaneous. (I have translated A68 terminology like "mode" and "name" to their modern equivalents "type" and "pointer".) You can read either chapter by chapter, which is more suitable for learning the language, or by subchapters in corresponding chapters, which is more suitable for understand its principles.
