SCM_ASSERT_TYPE (tr, context, SCM_ARG1, __FUNCTION__, "Context");
SCM_ASSERT_TYPE (scm_is_symbol (name), name, SCM_ARG2, __FUNCTION__, "symbol");
SCM_ASSERT_TYPE (tr, context, SCM_ARG1, __FUNCTION__, "Context");
SCM_ASSERT_TYPE (scm_is_symbol (name), name, SCM_ARG2, __FUNCTION__, "symbol");