Re: [PT] question on ND and sequents

On May 31, 2005, at 12:28 PM, Adrian Rezus wrote:
>  a small detail (prof. tait -- absent-minded this afternoon, likely
>  -- was
>  not very careful in stating such trifles, I guess!):

You are possibly right about my absent-mindedness: I can't remember.
But please tell me what I absent-mindedly overlooked in  stating that
Gentzen's first consistency proof in effect involves a formulation of
natural deduction using sequents.

Your earlier posting on Lukasiewicz's invention of natural deduction
is interesting. Do you mean that he explicitly wrote down a complete
set of rules of inference governing sequents? (Studia Logica 1934 is
not easily available to me now.) Your reference to Hertz does not
reassure me on this point. Truth----I should probably say credit for
truth----is ultimately in the details one presents.

   Sincere regards,

Bill Tait (I think)