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• CommentRowNumber1.
• CommentAuthorDavid_Corfield
• CommentTimeApr 17th 2017

Strangely, we don’t seem to have an nForum discussion for probability theory.

I added a reference there to

It replaces the category of measurable spaces, which isn’t cartesian closed, with the category of quasi-Borel spaces, which is. As they point out in section IX, what they’re doing is working with concrete sheaves on an established category of spaces, rather like the move to diffeological spaces.

[Given the interest in topology around these parts at the moment, we hear of ’C-spaces’ as generalized topological spaces arising from a similar sheaf construction in C. Xu and M. Escardo, “A constructive model of uniform continuity,” in Proc. TLCA, 2013.]

• CommentRowNumber2.
• CommentAuthorDavid_Corfield
• CommentTimeAug 22nd 2019

Anonymous

• CommentRowNumber4.
• CommentAuthorUrs
• CommentTimeNov 2nd 2020

• CommentRowNumber5.
• CommentAuthorUrs
• CommentTimeMar 29th 2021

I gave the existing list of references a subsection “References – General” and then added below that “References – As Euclidean field theory”. There I added pointer to the recent:

Of course, many more pointers must go here, to do this justice. But I leave it at that for the moment

• CommentRowNumber6.
• CommentAuthorGuest
• CommentTimeDec 1st 2021

In “Probability theory” under nPOV view, one can read: $\forall x \in X . \lambda B \in \Sigma_Y . h(x, B)$ What does the lambda mean? Perhaps we should note what it is as it seems not to be the only widely accepted standard in probability theory textbooks. Greetings, PJ

• CommentRowNumber7.
• CommentAuthorUrs
• CommentTimeDec 1st 2021

I don’t know, but just to note that the paragraph in question originates all the way from rev 1 back in May 2010 and seems to have been essentially untouched since.

• CommentRowNumber8.
• CommentAuthorRichard Williamson
• CommentTimeDec 1st 2021
• (edited Dec 1st 2021)

The revision was written by David C, but the notation seems to come from the paper of Panangaden. I believe it is just an unnecessarily formal/complicated way to describe the function $x \mapsto h(x,B)$, i.e. the condition is that for all $B \in \Sigma_Y$, this function (which goes from $X$ to $\left[ 0, 1 \right]$) is bounded measurable.

• CommentRowNumber9.
• CommentAuthorGuest
• CommentTimeDec 1st 2021

Thanks for your answers. The lambda seems to come from the Lambda calculus. (c. f. here: https://en.wikipedia.org/wiki/Lambda_calculus) and seems to be really a way to notate functions. To be honest, I never worked with Lambda calculus and do not know if it is common knowledge. Greetings, PJ

• CommentRowNumber10.
• CommentAuthorDavid_Corfield
• CommentTimeDec 1st 2021

Richard is right in #8. But the page needs a complete make-over. There’s a huge number of papers in this area. I wonder if we could entice someone like Tobias Fritz to help out.