ABSTRACT
Frege’s only deduction rule was the modus ponens, and those propositions forming the Kern are what we now call axiom s. So there were nine axiom s, and as Frege only used the propositional connectives -> and (though in a different and actually two-dim ensional notation), there were six propo sitional axiom s, namely (dO) [Frege’s (1 .] , (d l) [Frege’s (2 .] , (d5) [Frege’s (8 .] , (m l) [Frege’s (4 1 .] , (m2) [Frege’s (2 8 .] , (c l) [Frege’s (3 1 .] . From these axiom s Frege derived all other tautologies he considered.
