1
import Control.Parallel
2

3
main = a `par` b `par` c `pseq` print (a + b + c)
4
    where
5
        a = ack 3 10
6
        b = fac 42
7
        c = fib 34
8

9
fac 0 = 1
10
fac n = n * fac (n-1)
11

12
ack 0 n = n+1
13
ack m 0 = ack (m-1) 1
14
ack m n = ack (m-1) (ack m (n-1))
15

16
fib 0 = 0
17
fib 1 = 1
18
fib n = fib (n-1) + fib (n-2)
19