-alias symbol "eq" (instance 0) = "leibnitz's equality".
-alias symbol "plus" (instance 0) = "natural plus".
-alias symbol "times" (instance 0) = "natural times".
+alias symbol "eq" (instance 0) = "Coq's leibnitz's equality".
+alias symbol "plus" (instance 0) = "Coq's natural plus".
+alias symbol "times" (instance 0) = "Coq's natural times".