Update labs_04.md

labs/labs_04.md

@@ -25,7 +25,7 @@ That is, we explicitly replace strings by fresh identifiers which will
 prevent us from mixing up definitions of the same name, or referring to
 things that have not been defined. Amy\'s name analyzer is provided to
 you as part of this lab\'s skeleton, but you should read the [dedicated
-name analyzer page](name analyzer) to understand how it works.
+name analyzer page](NameAnalysis.md) to understand how it works.
 
 ## Introduction to Type Checking
 
@@ -154,4 +154,4 @@ You can use the following command (from the root of your repository) to generate
 zip -r submission-<groupNumber>.zip src/
 ```
 
-You can then verify the content of the archive using `unzip -l submission-<groupNumber>.zip`
\ No newline at end of file
+You can then verify the content of the archive using `unzip -l submission-<groupNumber>.zip`