Backout ö and one other change is it fails with asciidoctor-pdf

Author: krlawrence

book/Gremlin-Graph-Guide.adoc

@@ -344,10 +344,10 @@ very nature, the air routes network used as the basis for all of the examples in
 this book being a perfect example of such a situation.
 
 Those of you that looked at graphs as part of a computer science course are correct
-if your reaction was "haven't graphs been around for ages?" Indeed, Leonard Euler is
-credited with demonstrating the first graph problem and inventing the whole concept
-of "Graph Theory" all the way back in 1763 when he investigated the now famous
-"Seven Bridges of Königsberg" problem.
+if your reaction was "Surely graphs have been around for ages, why is this considered
+new?". Indeed, Leonard Euler is credited with demonstrating the first graph problem
+and inventing the whole concept of "Graph Theory" all the way back in 1763 when he
+investigated the now famous "Seven Bridges of Koenigsberg" problem.
 
 If you want to read a bit more about graph theory and its present-day application,
 you can find a lot of good information online. Here's a Wikipedia link to get you