The title of this book contains the words ALGORITHMIC LANGUAGE, in the
singular. This is meant to convey the idea that it deals not so much
with the diversity of program- ming languages, but rather with their
commonalities. The task of formal program develop- It allows classifying
ment proved to be the ideal frame for demonstrating this unity. concepts
and distinguishing fundamental notions from notational features; and it
leads immediately to a systematic disposition. This approach is
supported by didactic, practical, and theoretical considerations. The
clarity of the structure of a programming language de- signed according
to the principles of program transformation is remarkable. Of course
there are various notations for such a language. The notation used in
this book is mainly oriented towards ALGOL 68, but is also strongly
influenced by PASCAL - it could equally well have been the other way
round. In the appendices there are occa- sional references to the styles
used in ALGOL, PASCAL, LISP, and elsewhere.