VMS Help RTL Routines, MTH$, BLAS1$VxDOTx, Returns  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    OpenVMS usage:floating_point or complex_number
    type:         F_floating, D_floating, G_floating real or
                  F_floating, D_floating, G_floating complex
    access:       write only
    mechanism:    by value

    The function value, called dotpr, is the dot product of two n-
    element vectors, x and y. Specify the same data type for dotpr
    and the argument x.