diff --git a/src/ontologies/math_exam/Nmath_exam.thy b/src/ontologies/math_exam/Nmath_exam.thy
index 888e29d..6242765 100644
--- a/src/ontologies/math_exam/Nmath_exam.thy
+++ b/src/ontologies/math_exam/Nmath_exam.thy
@@ -146,7 +146,7 @@ solution > subsolution
  - proof derivation
 
 marking > submarking
-  
+    
 grade
 
 Invarianten: