%{
#include <stdio.h>
#include <string.h>
void yyerror( const char *msg);	/* called for parser syntax error */
int yylex( void);		/* declare to avoid gcc warnings */

#define YYSTYPE double

%}

%token NUMBER

%%
list:	/* nothing, matches before start of input */
	| list '\n' /* empty line */
	| list expression '\n'
	{
	  printf( "%g\n", $2);
	}
	| list error '\n'
	{
	  yyerrok;
	}
	;

primary_expression:
	NUMBER
	| '(' expression ')'
	{
	  $$ = $2;
	}
	;
	
multiplicative_expression:
	primary_expression
	| multiplicative_expression '*' primary_expression
	{
	  $$ = $1 * $3;
	}
	;

additive_expression:
	multiplicative_expression
	| additive_expression '+' multiplicative_expression
	{
	  $$ = $1 + $3;
	}
	;

expression:
	additive_expression
	;
%%

int main( int argc, char *argv[])
{
  return yyparse();
}