The Sylvester graph of a configuration is the set of Ordinary Points and Ordinary Lines.
See also Ordinary Line, Ordinary Point
References
Guy, R. K. ``Monthly Unsolved Problems, 1969-1987.'' Amer. Math. Monthly 94, 961-970, 1987.
Guy, R. K. ``Unsolved Problems Come of Age.'' Amer. Math. Monthly 96, 903-909, 1989.