# David Corfield explanation, evidence, cause

What did I see in lenses and modality?

So a lens (in cs) is just an algebra for what I called the possibility monad in my SYCO 1 talk - https://ncatlab.org/davidcorfield/files/ModalBirm.pdf? If so, curious that @_julesh_ , the other invited speaker, told us about these, while I dwelt on coalgebras for the necessity comonad. Dual talks.

Does the lenses literature intersect with that of type refinement: https://ncatlab.org/nlab/show/type+refinement? A refinement is a lift over a morphism in the base, which seems much like what’s happening with a bimorphic lens (S, T) -> (A, B).

S is fibred over A, and T over B, and you want to know where to send an element of S in T, given an element of B.

Perhaps ‘Positive Subtyping’, https://doi.org/10.1006/inco.1996.0031.

Evidence as three part relation, evidence for something in this context.

Chang and Fisher on two kinds of evidence: proposition-proposition, process-trace.

MacIntyre on cause as four place relation, A is cause of B against background C, when otherwise would have happened.

Does this explain difference-making and production?

Jaynes, Probability of A given B in context of background information.

Evidence not reducible to propositions, but to way enquiry is organised.

DTT and conditional probability.

van Fraassen on explanation and contrast.

DTT and questions.

Last revised on December 1, 2020 at 12:19:25. See the history of this page for a list of all contributions to it.