Computational Aristotelian Term Logic - Part 1 of 3

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This site is devoted to the formal aspects of traditional Aristotelian logic. The Aristotelian system together with its enhancements has been the predominant logic in Europe during more than 2000 years.

Aristotle's logic is a perfect formal system of its own, which is independent of modern propositional or predicate logic. This site is a "living proof" for this assertion which has been put forward convincingly by Freytag-Löringhoff, Lukasiewicz, Smiley, Corcoran and many other scholars since more than 50 years.

Our online program provides a platform for experimentation and research on Aristotelian logic. We have implemented the classical syllogistic theory by means of a rule based computer program which realises the modern approach of considering Aristotle's logic as a "system of natural deduction."



Enter propositions: Input language: These are the main rules for feeding the program with input propositions:
  • Propositions have the form A(x,y), E(x,y), I(x,y), O(x,y). They may be inserted anywhere into the input box.
  • Propositions are separated by space (one or more blanks).
  • The terms x, y , z ,.. in a proposition may be any string of characters. Thus, A(man,animal) is a well formed proposition.
  • If both terms in a proposition are constituted of only one character each, for example, A(M,N), then you may delete the brackets and simply write AMN.
  • Text included in /* and */ will be taken as commentary.
All x are y:
Some x are y:
A(x,y)
I(x,y)
     Example To Part 2   To Part 3
No x is y:
Some x are not y:
E(x,y)
O(x,y)
© Klaus Glashoff, 2004 Last update: June 3., 2009