diff -r e050178e1048 -r 549001f2401d src/Tools/isac/calcelems.sml
--- a/src/Tools/isac/calcelems.sml	Thu Jun 19 08:12:08 2014 +0200
+++ b/src/Tools/isac/calcelems.sml	Thu Jun 19 08:15:50 2014 +0200
@@ -879,23 +879,22 @@
 		      "consider setting 'check_guhs_unique := false'")
     else ();
 
-fun insrt _ pbt [k] [] = [Ptyp (k, [pbt],[])]
-  | insrt d pbt [k] ((Ptyp (k', [p], ps))::pys) =
-((*tracing("### insert 1: ks = "^(strs2str [k])^"    k'= "^k');*)
-     if k=k'
-     then ((Ptyp (k', [pbt], ps))::pys)
-     else (*ev.newly added pbt is free _only_ with 'last_elem pblID'*)
-	 ((Ptyp (k', [p], ps))::(insrt d pbt [k] pys))
-)			 
+fun insrt _ pbt [k] [] = [Ptyp (k, [pbt], [])]
+  | insrt d pbt [k] ((Ptyp (k', [p], ps)) :: pys) =
+      ((*writeln ("### insert 1: ks = " ^ strs2str [k] ^ "    k'= " ^ k');*)
+      if k = k'
+      then ((Ptyp (k', [pbt], ps)) :: pys)
+      else  ((Ptyp (k', [p], ps)) :: (insrt d pbt [k] pys))
+      )			 
   | insrt d pbt (k::ks) ((Ptyp (k', [p], ps))::pys) =
-((*tracing("### insert 2: ks = "^(strs2str (k::ks))^"    k'= "^k');*)
-     if k=k'
-     then ((Ptyp (k', [p], insrt d pbt ks ps))::pys)
-     else 
-	 if length pys = 0
-	 then error ("insert: not found "^(strs2str (d:pblID)))
-	 else ((Ptyp (k', [p], ps))::(insrt d pbt (k::ks) pys))
-);
+      ((*writeln ("### insert 2: ks = "^(strs2str (k::ks))^"    k'= "^k');*)
+      if k = k'
+      then ((Ptyp (k', [p], insrt d pbt ks ps)) :: pys)
+      else 
+        if length pys = 0
+        then error ("insert: not found " ^ (strs2str (d : pblID)))
+        else ((Ptyp (k', [p], ps)) :: (insrt d pbt (k :: ks) pys))
+      );
 
 fun update_ptyps ID _ _ [] =
     error ("update_ptyps: " ^ strs2str' ID ^ " does not exist")