description
The Preprint Nr. 227 (Department of Mathematics, University of Utrecht, January 1982; actually dated: 9 October 1981, 35 pp.) is identical with the published version (in: Libertas Mathematica, redigit Constantin Corduneanu, Romanian American Academy of Arts and Sciences, Arlington Texas, tomus II, 1982, pp. 63--97), except for the following four-line note, added in print on proof-reading: “Added in proof (September 6, 1982). David Meredith noticed, in correspondence, that the formula j := CCpCCqqCpCqCpq falsifies our Conjecture 25. This suggests that R-> [= the implicational fragment of R] may possess axiomatizations satisfying the hypotheses of Theorem 19 and / or Corollary 20, but does not alter the content of our discussion in 4.”