diff --git a/examples/math_exam/BAC2017.thy b/examples/math_exam/BAC2017.thy
index cbae2cf..63cd2ba 100644
--- a/examples/math_exam/BAC2017.thy
+++ b/examples/math_exam/BAC2017.thy
@@ -5,6 +5,7 @@ begin
    
 open_monitor*[exam::MathExam] 
 
+
 section*[idir::Author,affiliation="''CentraleSupelec''", 
 email="''idir.aitsadoune@centralesupelec.fr''"]
 {*Idir AIT SADOUNE*}
@@ -13,7 +14,8 @@ section*[keller::Author,affiliation="''LRI, Univ. Paris-Sud''",
 email="''Chantal.Keller@lri.fr''"]
 {*Chantal KELLER*}
 
-subsection*[header::Header,examSubject= "[algebra,geometry]", 
+
+section*[header::Header,examSubject= "[analysis,geometry]", 
  examTitle="''BACCALAUREAT GENERAL MATHEMATIQUES''", 
 date="''21-06-2017''", 
 timeAllowed="240::int"]
@@ -27,8 +29,10 @@ timeAllowed="240::int"]
 \end{itemize}
 *}
 
-subsubsection*[exo1 :: Exercise,Exercise.concerns= "{examiner,validator,student}",
-Exercise.content="[q1::Task,q2,q3a]"]
+
+subsection*[exo1 :: Exercise,
+    Exercise.concerns= "{examiner,validator,student}",
+    Exercise.content="[q1::Task,q2,q3a]"]
 {* 
 On considère la fonction h définie sur l’intervalle [0..+\<infinity>] par : @{term "h(x) = x * exponent (-x)"}
 *}
@@ -36,7 +40,7 @@ On considère la fonction h définie sur l’intervalle [0..+\<infinity>] par :
 definition h :: "real \<Rightarrow> real"
   where "h x \<equiv> x * exp (- x)"
 
-  
+ 
 subsubsection*[q1::Task, Task.concerns= "{examiner,validator,student}",
 level="oneStar", mark="1::int", type="formal"] 
 {* Déterminer la limite de la fonction @{term h} en +\<infinity>. *}
@@ -47,17 +51,19 @@ text*[a1::Answer_Formal_Step]
 lemma q1 : "(h \<longlongrightarrow> (0::real)) at_top"
   sorry
 
+subsubsection*[v1::Validation,
+    proofs="[q1::thm]"]
+  {* See lemma q1 *}
+
   
 subsubsection*[q2::Task, Task.concerns= "{examiner,validator,student}",
 level="oneStar", mark="1::int", type="formal"] 
 {* Étudier les variations de la fonction @{term h} sur l'intervalle [0..+\<infinity>] et dresser son tableau
    de variation *}
 
-
 text*[a2::Answer_Formal_Step]
 {* Fill in term and justification*}
 
-
 definition h' :: "real \<Rightarrow> real"
   where "h' x \<equiv> (1 - x) * exp (- x)"
 
@@ -73,26 +79,40 @@ proof -
     by (metis "***" left_diff_distrib mult_minus_right uminus_add_conv_diff)
 qed
 
-
 lemma q2_b : "0 \<le> x \<and> x \<le> y \<and> y \<le> 1 \<Longrightarrow> h x \<le> h y"
   sorry
 
-
 lemma q2_c : "1 \<le> x \<and> x \<le> y \<Longrightarrow> h x \<ge> h y"
   sorry
 
+subsubsection*[v2::Validation,
+    proofs="[q2_b::thm, q2_c]"]
+  {* See lemmas q2_b and q2_c *}
+
 
 subsubsection*[q3a::Task, Task.concerns= "{examiner,validator,student}",
 level="oneStar", mark="1::int", type="formal"] 
 {* Vérifier que pour tout nombre réel x appartenant à l'intervalle [0..+\<infinity>], on a :
    @term{h x = (exp (- x)) - (h' x)} *}
 
+text*[a3a::Answer_Formal_Step]
+{* Fill in term and justification*}
+
 lemma q3a : "h x = (exp (- x)) - (h' x)"
   by (simp add : h_def h'_def left_diff_distrib)
 
+subsubsection*[v3a::Validation,
+    proofs="[q3a::thm]"]
+  {* See lemma q3a *}
+
+
+subsection*[sol1 :: Solution,
+    Solution.content="[exo1::Exercise]",
+    Solution.valids = "[v1::Validation,v2,v3a]"]
+{* 
+See validations.
+*}
 
-text*[a3a::Answer_Formal_Step]
-{* Fill in term and justification*}
 
 
 close_monitor*[exam] 
diff --git a/ontologies/mathex_onto.thy b/ontologies/mathex_onto.thy
index 09846ca..2d0098d 100644
--- a/ontologies/mathex_onto.thy
+++ b/ontologies/mathex_onto.thy
@@ -7,7 +7,7 @@ doc_class Author =
    email :: "string"
 
 datatype Subject =
-  algebra | geometry | statistical
+  algebra | geometry | statistical | analysis
 
 datatype Level =
   oneStar | twoStars | threeStars