LEX和YACC编写的标准PASCAL语法，bnf形式。-* Pascal grammar in Yacc format, based originally on BNF given in "Standard Pascal-- User Reference Manual", by Doug Cooper. This in turn is the BNF given by the ANSI and ISO Pascal standards, and so, is PUBLIC DOMAIN. The grammar is for ISO Level 0 Pascal. The grammar has been massaged somewhat to make it LALR, and added the following extensions.