Units of measurement

[<Measure>]
type kg

[<Measure>]
type m

[<Measure>]
type s

[<Measure>]
type N = kg m/s^2

let mul (a : float<kg>) (b : float<m/s^2>) : float<N> =
  a * b

printfn "%f\n" (mul 5.0<kg> 2.0<m/s^2>)