add forum link

diff --git a/ralf/_posts/2019-05-15-typeclasses-exponential-blowup.md b/ralf/_posts/2019-05-15-typeclasses-exponential-blowup.md
index 4c4c0a0ba1bef46472f030520b31d8e8fb206f9a..e59917b87ed92336f88e3925decffd72432179e5 100644 (file)
--- a/ralf/_posts/2019-05-15-typeclasses-exponential-blowup.md
+++ b/ralf/_posts/2019-05-15-typeclasses-exponential-blowup.md
@@ -1,6 +1,7 @@
 ---
 title: "Exponential blowup when using unbundled typeclasses to model algebraic hierarchies"
 categories: research coq
+forum: https://coq.discourse.group/t/blog-post-exponential-blowup-when-using-unbundled-typeclasses-to-model-algebraic-hierarchies/289
 ---
 
 When formalizing a proof in an interactive theorem prover like [Coq](https://coq.inria.fr/), one reoccuring issue is the handling of algebraic hierarchies.