Update index.md

teaching/2023/cs422/index.md

@@ -92,6 +92,14 @@ Note: See the [abort](https://github.com/runtimeverification/k/tree/master/k-dis
   - http://matching-logic.org
   - [Marktoberdorf Lecture Notes](https://events.model.in.tum.de/mod23/lectures.html)
 
+---
+
+- ***SIMPLE: Designing Imperative Programming Languages***
+  - [SIMPLE untyped, statically typed, and dynamically typed](https://kframework.org/k-distribution/pl-tutorial/) (Part 7 of the K Tutorial). Click [here](https://github.com/kframework/k/tree/master/k-distribution/pl-tutorial/2_languages/1_simple) to see the code on GitHub.
+  - [K Tutorial, Part 5: Defining type systems](https://kframework.org/k-distribution/pl-tutorial/) (this is optional at this stage, but instructive for better understanding the static semantics; read at least Lesson 1, and skim Lesson 6). Click [here](https://github.com/kframework/k/tree/master/k-distribution/pl-tutorial/1_k/5_types) to see the code on GitHub. 
+  - [K Overview]({{site.baseurl}}/assets/CS422-K-Overview.pdf) paper, which also defines and explains SIMPLE. Sections 3 and 4 (the other sections were covered above)
+
+
 ---
 ... more to come ...
 ---