-struct expression *expr_parse (struct lexer *lexer, struct pool *,
- struct dataset *, enum val_type);
-struct expression *expr_parse_bool (struct lexer *lexer, struct pool *,
- struct dataset *);
-struct expression *expr_parse_new_variable (struct lexer *lexer, struct pool *,
- struct dataset *,
+struct expression *expr_parse (struct lexer *, struct dataset *, enum val_type);
+struct expression *expr_parse_bool (struct lexer *, struct dataset *);
+struct expression *expr_parse_new_variable (struct lexer *, struct dataset *,