Fix MarkDown typo
diff --git a/doc/spec/rac-spec.md b/doc/spec/rac-spec.md
index fbd45f9..a9d6c7d 100644
--- a/doc/spec/rac-spec.md
+++ b/doc/spec/rac-spec.md
@@ -267,7 +267,7 @@
A child `Branch Node`'s `SubBranch COffset` is defined to be `COff[a]`. Its
`SubBranch DBias` and `SubBranch DOffMax` are defined to be `DOff[a]` and
-`DOff[a+1].
+`DOff[a+1]`.
- When `(STag[a] < Arity)`, it is a `CBiasing Branch Node`. The `SubBranch
CBias` is defined to be `(Branch_CBias + CPtr[STag[a]])`. This expression
@@ -547,4 +547,4 @@
---
-Updated on April 2019.
+Updated on August 2019.
