-struct expression *expr_parse (struct dictionary *, enum expr_type);
-struct expression *expr_parse_pool (struct pool *,
- struct dictionary *, enum expr_type);
+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 *,
+ const char *new_var_name);