OpenVMS usage:complex_number
    type:         F_floating complex, D_floating complex, G_floating
                  complex, IEEE S_floating complex, IEEE T_floating
                  complex
    access:       write only
    mechanism:    by value

    Result of raising a complex base to a complex exponent. OTS$POWCC
    returns an F-floating complex number. OTS$POWCDCD_R3 returns a
    D-floating complex number. OTS$POWCGCG_R3 returns a G-floating
    complex number. OTS$POWCSCS returns an IEEE S-floating complex
    number. OTS$POWCTCT_R3 returns an IEEE T-floating complex number.