// module M1
import "Prelude"

foo :: Ring a => Boolean -> a -> a
foo True v = v+1
foo False v = v+1 
--
// module M2
import "Prelude"

foo :: Ring a => String -> a -> a
foo cond v = if cond=="true"
             then v+1
             else v-1 
--
import "Prelude"
import "M1"
import "M2"

main = foo False (foo "True" 10) :: Integer
--
10