fix

courses/ai1sysproj.md

@@ -12,7 +12,7 @@ semesters:
 The AI-1 Systems Project aims to provide hands-on experience for the topics covered in the [Artificial Intelligence 1 lecture](/courses/ai1/).
 That includes the implementation of algorithms for specific problems and the use of existing tools.
 
-The [Artificial Intelligence 1 lecture](/courses/ai1/) ([last year's lecture notes for AI 1 & 2](/teaching/AI/notes-2019-20.pdf)
+The [Artificial Intelligence 1 lecture](/courses/ai1/) ([last year's lecture notes for AI 1 & 2](/teaching/AI/notes-2019-20.pdf))
 is not a strict requirement but we do recommend to take it as we will not teach the topics again in the project.
 Note that the project will generally be paced more slowly than the lecture, i.e. you can take the project and the lecture in parallel.