[Pharo-project] Pharo by example book: copying/pasting code snippets

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