A Nonrecursive Method of Syntax Specification
The use of the Kleene regular expression notation
for describing algebraic language syntax, 
in particular of ALGOL, is described in this paper. 
A FORTRAN II computer program for carrying out the 
elimination algorithm of Gorn,similar to Gaussian elimination
for linear systems of algebraic equations, 
is described.  This was applied to numerous smaller
languages, including some sublanguage of ALGOL.  
A hand calculation result of the application of the algorithm
to all of ALGOL is given, thus expressing 
the Revised ALGOL 1960 syntax in completely nonrecursive
terms, as far as its context-free portion is 
concerned.  This description in many ways is far more
intuitively understood than the previous recursive 
description, it is suggested.  The paper also includes
results of the machine program, which does not 
include a simplification algorithm.
CACM April, 1966
Carr III, J. W.
Weiland, J.
