gistfile1.fs

namespace Math

    type IPhoton =
        abstract EnergyByWavelength : float -> float -> float
        abstract EnergyByFrequency : (float * float) -> float
// ----------------------------------^ Specifying tupled params

    type Photon = 
        

        member x.h = 6.62606896e-34
        member x.c = 2.99792458e8

        interface IPhoton with
            member x.EnergyByWavelength lambda multiplier = (x.h * x.c) / (lambda * multiplier)
            member x.EnergyByFrequency (nu, multiplier) = x.h * (nu * multiplier)
// ------------------^ Error: This override takes a different number of arguments to the corresponding abstract member