Among other things, this has bothered me, but, I realize it is too late to fix, and trying to fix it could take forever, but Stefan used the "y" axis incorrectly...
For example, if the value of the x axis = 3 & y axis = 3, it would be like this:
............|..............
............|............*
............|..............
............|..............
----------------------
............|..............
............|..............
............|............%
............|..............
The asterix ('*') is where it should be, but according to the Graal engine, it would place it where the percentage sign ('%') is. Just telling you this, for the next program you make, so it's less confusing, thanks, bye.