When I copy and paste code snippets from the book, the compiler complains about the minus signs (which is different character from what Pharo expects):

For example the line from the book:
(j > 1) ifTrue: [ (cells at: i at: j − 1) toggleState].
I have to change to (with "short" minus sign)
(j > 1) ifTrue: [ (cells at: i at: j - 1) toggleState].
Otherwise the method doesn't get accepted.
I wonder if this is a PDF issue and if it could be corrected?

Thank you,
Andrew