void check_result(lua_State * L, int result) {
if (result) {
if (is_exception(L, -1)) {
to_exception(L, -1).rethrow();
} else {
throw script_exception(lua_tostring(L, -1));
}
}
}
void exception_node::execute( proof_context& ctx )
{
throw script_exception( t );
}