Haskell question

[Scott]

Hello!
   I am reading Discrete Mathematics Using a computer by Hall and O'Donnell 
and in the introduction to hugs section, they give this example:
[[x,y] | x<-[1..50],y<-[1..50],z<-[1..50],x**2+y**2==z**2]
now I type it in and expect it to return a number of results, but it 
doesn't, it shows:
[[8.0,15.0,17.0],[14.0,48.0,50.0],[15.0,8.0,17.0],[15.0,20.0,25.0],[20.0,15.0,25.0],[21.0,28.0,35.0],[27.0,36.0,45.0],[28.0,21.0,35.0],[30.0,40.0,50.0],[36.0,27.0,45.0],[40.0,30.0,50.0],[48.0,14.0,50.0]]
My question is where is [3.0,4.0,5.0],[5.0,12.0,13.0]?
I have looked everywhere I could think of to see what I am doing wrong, but 
I have no idea.  Maybe a rounding error somewhere?
Thank you,
  Scott Anderson