3 ms·

> Simplest counterexample: (l,r) = (1,0) Then r-l is 0-1, which underflows. ghci> (0 :: Word) - (1 :: Word) 18446744073709551615

• jonsen 4y ago
  So is it not true that it is not true?
  • moonchild 4y ago
    18446744073709551615 is greater than 1, isn't it?
    • jonsen 4y ago
      Ah, of course, sorry!
• tromp 4y ago
  > Then r-l is 0-1, which underflows. True. Then (l,r) = (18446744073709551615,0) is a counterexample, since r-l = 1.