Re: Gödel's system P, Principia Mathematica, and the reducibility axiom

On 2008-01-28, in sci.logic, Rupert wrote:
Presumably, the people who did this work would have had to formulate
a precise definition of the ramified theory of types. It would be
interesting to have a look at that. I should chase it up one of
these days.

It is not at all difficult to give a formalisation of the ramified
theory of types. The question is to what extent the straightforward
formalisation captures the system of Principia -- a question that is
of more historical than mathematical interest.

In any case, do share whatever references you manage to dig up.

--
Aatu Koskensilta (aatu.koskensilta@xxxxxxxxx)

"Wovon man nicht sprechen kann, daruber muss man schweigen"
- Ludwig Wittgenstein, Tractatus Logico-Philosophicus
.