> Dear all,
> A1, A2, ... , An
> Does anyone know who was the first to use the ----------------------
> syntax on the right for proof rules (Ai are C
> antecedents and C is the conclusion) ?
I do not now about the first occurrence. The general form stated here
does occur in the introduction of Gerhard Gentzen's "Untersuchungen u"ber
das logische Schliessen" , Math.Z. 39 (1934) 176-210 .
S
As precursor one may count the notation for the rule S -> T
of modus ponens in Hilbert's "Neubegru"ndung der ------
Mathematik", Abhandl.Math.Seminar Hamburg Univ. 1 (1922) T
157-177, appearing there on p. 168 (with German letters S, T).
Other rules written this way (with latin letters) appear in Paul Hertz'
"Axiomensysteme fu"r beliebige Satzszsteme 1.Teil", Math.Ann. 87 (1922)
246-263 .
W.F.