let pol a b c =
    let p=(a+.b+.c)/.2.0 in sqrt(p*.(p-.a)*.(p-.b)*.(p-.c));;

let test a b c =
    (a+.b)>c &&(b+.c)>a &&(a+.c)>b

let main a b c =
    let w=test(a b c) in(
    if w
     then pol (a b c)
     else raise(Failure "Error"));;

# let f a b = a + b;;
val f : int -> int -> int = <fun>
# f 3 8;;
- : int = 11

# f (3 8);;
Error: This expression has type int
       This is not a function; it cannot be applied.