%token SYMBOLE
%left '|'
%left CONCAT
%left '*'
%%
expr :  '(' expr ')'    {$$ = $2;}
    | expr expr  %prec CONCAT { $$=ab_construire('.',$1,$2);}
    | expr '|' expr   {$$= ab_construire('|',$1,$3);}
    | expr '*' {$$= ab_construire('*',$1,ab_creer());}
    | SYMBOLE {$$=ab_construire(yylval.i, ab_creer(), ab_creer());}
;