Details

The first use of binary trees to represent Boolean functions were Macfarlane's diagrams that he called "logical spectra" [5, p. 44]. The representation is more compact than using truth tables.

References

[1] R. Audi, ed., The Cambridge Dictionary of Philosophy, Cambridge: Cambridge University Press, 1995 pp. 780–782.

[2] L. Borkowski, Elementy logiki formalnej (Elements of Formal Logic, in Polish), 3rd ed., Warsaw: Wyd, 1976.

[3] L. Carroll, Symbolic Logic and the Game of Logic, New York: Dover, 1958.

[4] I. M. Copi and C. Cohen, Introduction to Logic, 9th ed., New York: Macmillan, 1994 pp. 214–218.

[5] M. Gardner, Logic Machines, Diagrams and Boolean Algebra, New York: Dover Publications, 1968.