1.1 --- a/src/Tools/isac/MathEngBasic/ctree-basic.sml	Tue Dec 20 08:11:26 2022 +0100
     1.2 +++ b/src/Tools/isac/MathEngBasic/ctree-basic.sml	Wed Dec 21 18:48:23 2022 +0100
     1.3 @@ -379,10 +379,10 @@
     1.4    | children _ = raise ERROR "children: uncovered fun def.";
     1.5  
     1.6  (*/--------------- duplicates in ctree-navi.sml: required also here below ---------------\*)
     1.7 +\<^isac_test>\<open>
     1.8  fun lev_up [] = raise PTREE "lev_up []"
     1.9    | lev_up p = (drop_last p):pos;
    1.10  (* find the position of the next parent which is a PblObj in ctree *)
    1.11 -\<^isac_test>\<open>
    1.12  fun par_pblobj _ [] = []
    1.13    | par_pblobj pt p =
    1.14      let