ɐn ˈɜːli ɛɡzˈæmpəl ʌv sˈʌtʃ ɐ sˈɪstəm, fˈɜːst pɹəpˈoʊzd baɪ kˈɛnəθ dʒˈɑːn fɹˈɔst ɪn nˈaɪntiːnhˈʌndɹɪd sˈɪksti tˈuː, ɪz ʃˈoʊn ɪnðə fˈɪɡjɚ.
An early example of such a system, first proposed by Kenneth John Frost in 1962, is shown in the figure.