src/HOL/ROOT

--- a/src/HOL/ROOT	Tue Jan 22 15:29:22 2019 +0100
+++ b/src/HOL/ROOT	Fri Dec 14 14:33:26 2018 +0100
@@ -625,6 +625,7 @@
     Transfer_Int_Nat
     Transitive_Closure_Table_Ex
     Tree23
+    Triangular_Numbers
     Unification
     While_Combinator_Example
     Word_Type