Hi why do I get?

cetin@linux-d312:~/lab/exp/1> ./eq
23
23
3
a = b = c = n1-0.8457820374040622n2-0.1542179625959377

when I run

import System.IO

main :: IO ()
main = do
  a ← ask "a"
  b ← ask "b"
  c ← ask "c"
  eval a b c

ask v = do
  putStr (v ++ " = ")
  readLn

eval a b c = do
  case delta < 0 of
    True  → putStr "neg"
    False → putStr ("n1" ++ show n1 ++ "n2" ++ show n2)
  where
    delta = b*b - 4*c*a
    n  o  = (-b `o` sqrt(delta))/(2*a)
    n1    = n (+)
    n2    = n (-)