Definitions of Two-Placed Connectives in Lesniewski's Protothetic

To describe his extended propositional calculus (protothetic), which is a logical system based on a single axiom, Leśniewski invented a special notation for a propositional function of two arguments . He used a circle and up to four lines around the circle, which point to those values of arguments of for which the function is true, according to the diagram:
The combinations of the four lines generate a Boolean algebra of 16 elements. As a consequence, let be the negation of ; then the sign for consists of the circle and the four lines that do not belong to the sign of .

SNAPSHOTS

  • [Snapshot]
  • [Snapshot]
  • [Snapshot]

DETAILS

The names of the propositional functions are taken from [1, pp. 19–20]. Disjunction and alternation are reversed with respect to modern usage. The protothetic axiom from 1926 was copied from [2, pp. 129].
References
[1] J. J. T. Srzednicki and Z. Stachniak, eds., S. Leśniewski's Lecture Notes in Logic, New York: Springer, 1988.
[2] S. McCall, ed., Polish Logic, 1920–1939, Oxford: Oxford University Press, 1967.
    • Share:

Embed Interactive Demonstration New!

Just copy and paste this snippet of JavaScript code into your website or blog to put the live Demonstration on your site. More details »

Files require Wolfram CDF Player or Mathematica.