-; senr_v_bobj := @T_Branch (option (senr_c_obj * senr_c_obj))
-; senr_v_bin : BinoidalCat senr_v senr_v_bobj
-; senr_v_pmon : PreMonoidalCat senr_v_bin senr_v_i
-; senr_v_mon : MonoidalCat senr_v_pmon
-; senr_c : ECategory senr_v_mon senr_c_obj senr_c_hom
-; senr_c_bin : EBinoidalCat senr_c
-; senr_c_i : senr_c
-; senr_c_pm : PreMonoidalCat senr_c_bin senr_c_i
+; senr_v_bobj := @T_Branch ??(senr_c_obj * senr_c_obj)
+; senr_v_bin : BinoidalCat senr_v senr_v_bobj
+; senr_v_pmon : PreMonoidalCat senr_v_bin senr_v_i
+; senr_v_mon : MonoidalCat senr_v_pmon
+; senr_c : ECategory senr_v_mon senr_c_obj senr_c_hom
+; senr_c_bobj : senr_c_obj -> senr_c_obj -> senr_c_obj
+; senr_c_bin : EBinoidalCat senr_c senr_c_bobj
+; senr_c_i : senr_c
+; senr_c_pm : PreMonoidalCat senr_c_bin senr_c_i