grammar.y

%{
	#include <stdio.h>	
	extern int yyerror(char* err);
	extern int yylex(void);
	extern FILE *yyin;
%}

%start seq

%token VAR
%token FUNC
%token PRAEDIKAT
%token ARROW
%token UND
%token KOMMA
%token TRUE
%token FALSE
%token KLAMMERO
%token KLAMMERC
%token NEWLINE

%%

term: VAR {printf("VAR -> term \n");}
	| FUNC {printf("FUNC -> term \n");}
	| FUNC KLAMMERO params KLAMMERC {printf("FUNC(params) -> term\n");}

params: term {printf("term -> params\n");}
	| term KOMMA params {printf("term , params -> params\n");}

atom: PRAEDIKAT {printf("PRAEDIKAT -> atom\n");}
	| PRAEDIKAT KLAMMERO params KLAMMERC {printf("PRAEDIKAT(params) -> atom\n");}

formel: body ARROW FALSE {printf("body -> FALSE -> formel\n");}
	| body ARROW atom {printf("body -> atom -> formel\n");}
	| TRUE ARROW atom {printf("TRUE -> atom -> formel\n");}

body: atom {printf("atom -> body\n");}
	| body UND atom {printf("body & atom -> body\n");}

seq: formel NEWLINE {printf("formel NEWLINE -> seq\n");}
	| seq NEWLINE formel {printf("seq NEWLINE formel -> seq\n");}
	| NEWLINE {printf("NEWLINE -> seq\n");}

%%
int yyerror(char* err)
{
	printf("Error: %s\n", err);
	return 0;
}

int main( int argc, char **argv )       
{
	++argv, --argc;
	if(argc > 0) 
	{
		yyin = fopen(argv[0], "r");
	}
	else
	{
		yyin = stdin;
	}
	return yyparse();
}