diff --git a/examples/simple/MathExam.thy b/examples/simple/MathExam.thy
index 03d7e14..d80493a 100644
--- a/examples/simple/MathExam.thy
+++ b/examples/simple/MathExam.thy
@@ -4,10 +4,12 @@ begin
    
 open_monitor*[exam::MathExam] 
 
-text*[idir::Author, affiliation="''CentraleSupelec''", email="''idir.aitsadoune@centralesupelec.fr''"]
+section*[idir::Author, affiliation="''CentraleSupelec''", 
+         email="''idir.aitsadoune@centralesupelec.fr''"]
 {*Idir AIT SADOUNE*}
 
-text*[header::Header,examSubject= "algebra",  examTitle="''Exam number 1''", date="''02-05-2018''",timeAllowed="90::int"]
+subsection*[header::Header,examSubject= "algebra",  examTitle="''Exam number 1''", 
+            date="''02-05-2018''", timeAllowed="90::int"]
 {* 
 \begin{itemize}
 \item Use black ink or black ball-point pen. 
@@ -16,7 +18,7 @@ text*[header::Header,examSubject= "algebra",  examTitle="''Exam number 1''", dat
 \end{itemize}
 *}
 
-section*[exo1 :: Exercise, Exercise.content="[q1::Question,q2::Question]"]
+subsubsection*[exo1 :: Exercise, Exercise.content="[q1::Question,q2::Question]"]
 {* 
 Here are the first four lines of a number pattern.
 \begin{itemize}
diff --git a/ontologies/mathex_onto.thy b/ontologies/mathex_onto.thy
index 7088970..2266bca 100644
--- a/ontologies/mathex_onto.thy
+++ b/ontologies/mathex_onto.thy
@@ -42,11 +42,11 @@ datatype ContentClass =
 doc_class Exam_item = 
   concerns :: "ContentClass set"  
 
-datatype SubQuestion = Item string
+type_synonym SubQuestion = string
  
-doc_class Answer_Formal =  Exam_item +
-  step_label :: string
-  "term"     :: "string" 
+doc_class Answer_Formal_Step =  Exam_item +
+  justification :: string
+  "term"        :: "string" 
   
 doc_class Answer_YesNo =  Exam_item +
   step_label :: string
@@ -55,16 +55,16 @@ doc_class Answer_YesNo =  Exam_item +
 datatype Question_Type =   
   formal | informal | mixed 
   
-doc_class Question = Exam_item +
+doc_class Task = Exam_item +
   level    :: Level
   type     :: Question_Type
-  subitems :: "(SubQuestion * (Answer_Formal + Answer_YesNo)list) list"
+  subitems :: "(SubQuestion * (Answer_Formal_Step list + Answer_YesNo)list) list"
   concerns :: "ContentClass set" <= "{examiner,validator,student}" 
   mark     :: int
    
 
 doc_class Exercise = Exam_item +
-  content  :: "(Question) list"
+  content  :: "(Task) list"
   concerns :: "ContentClass set" <= "{examiner,validator,student}"