diff -r bfabbaf915b1 -r 3da177a07c3e src/Tools/isac/Build_Isac.thy
--- a/src/Tools/isac/Build_Isac.thy	Fri Oct 25 16:07:15 2019 +0200
+++ b/src/Tools/isac/Build_Isac.thy	Sat Oct 26 13:03:16 2019 +0200
@@ -34,17 +34,22 @@
     ML_file rewrite.sml
 *)        "ProgLang/ProgLang"
 (*
-    theory Input_Descript imports "~~/src/Tools/isac/CalcElements/CalcElements"
-  theory Specify imports "~~/src/Tools/isac/ProgLang/ProgLang" Input_Descript
+  theory MathEngBasic imports
+    "~~/src/Tools/isac/ProgLang/ProgLang" "~~/src/Tools/isac/Specify/Input_Descript"
+    ML_file "calc-tree-elem.sml"
     ML_file model.sml
     ML_file mstools.sml
     ML_file "specification-elems.sml"
     ML_file istate.sml
     ML_file tactic.sml
-    ML_file "ctree-basic.sml" (*shift to base in common with Interpret*)
-    ML_file "ctree-access.sml"(*shift to base in common with Interpret*)
-    ML_file "ctree-navi.sml"  (*shift to base in common with Interpret*)
-    ML_file ctree.sml         (*shift to base in common with Interpret*)
+    ML_file "ctree-basic.sml"
+    ML_file "ctree-access.sml"
+    ML_file "ctree-navi.sml"
+    ML_file ctree.sml
+*)        "MathEngBasic/MathEngBasic"
+(*
+    theory Input_Descript imports "~~/src/Tools/isac/CalcElements/CalcElements"
+  theory Specify imports "~~/src/Tools/isac/ProgLang/ProgLang" Input_Descript
     ML_file ptyps.sml
     ML_file generate.sml
     ML_file calchead.sml