Update readme and work on SCM to C translator

README.md

@@ -1,5 +1,7 @@
 # SICP
 
+**This is currently (2021/06/11) work in progress.**
+
 These are my solutions to the CS classic [Structure and Interpretation of
 Computer Programs](https://mitpress.mit.edu/sites/default/files/sicp/index.html).
 I have looked up the answer for some exercises on the
@@ -11,7 +13,21 @@ execute `pacman -S mit-scheme` to install it. Then run the scripts via
 `mit-scheme --quiet < script.scm`. You can also use the shell script `./run
 script.scm`.
 
-**This is currently (2021/05/13) work in progress.**
+I haven't completely solved the following exercises.
+
+- Exercise 1.13. I wasn't able to do the proof.
+- Exercise 4.78. I managed to use the amb-evaluator for the query system, but it
+  does not work for joined queries.
+- Exercise 4.79. I did not attempt to solve this exercise because of not
+  finishing the previous one, and it is the last one in the chapter.
+- Exercise 5.52. I have implemented the basic structure of a Scheme to C
+  translator, but I only finished a basic proof-of-concept. Most of the
+  additional work would be similar to 5.51.
+
+I had a great time working through this book. I feel like my mental capabilities
+improved throughout the process, and finishing all the exercises gives me an
+incredible feeling of accomplishment. I have written short summaries for each of
+the chapters below.
 
 
 # Chapter 1