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- Discussion Type
- discussion topicquantum computation
- Category Latest Changes
- Started by Urs
- Comments 27
- Last comment by Urs
- Last Active Nov 9th 2022

stub for

*quantum computation*

- Discussion Type
- discussion topicFatimah Rita Ahmadi
- Category Latest Changes
- Started by Urs
- Comments 1
- Last comment by Urs
- Last Active Nov 9th 2022

- Discussion Type
- discussion topicD'Auria-Fre formulation of supergravity
- Category Latest Changes
- Started by Urs
- Comments 8
- Last comment by Urs
- Last Active Nov 9th 2022

crated D'Auria-Fre formulation of supergravity

there is a blog entry to go with this here

- Discussion Type
- discussion topicdefinition
- Category Latest Changes
- Started by nLab edit announcer
- Comments 11
- Last comment by Urs
- Last Active Nov 9th 2022

- Discussion Type
- discussion topicdefinitional equality
- Category Latest Changes
- Started by nLab edit announcer
- Comments 1
- Last comment by nLab edit announcer
- Last Active Nov 9th 2022

- Discussion Type
- discussion topicalpha-equivalence
- Category Latest Changes
- Started by nLab edit announcer
- Comments 2
- Last comment by nLab edit announcer
- Last Active Nov 9th 2022

Adding reference

- Roy L. Crole,
*Alpha equivalence equalities*, Theoretical Computer Science, Volume 433, 18 May 2012, Pages 1-19, (doi:10.1016/j.tcs.2012.01.030)

Anonymous

- Roy L. Crole,

- Discussion Type
- discussion topicconversion rule
- Category Latest Changes
- Started by nLab edit announcer
- Comments 3
- Last comment by nLab edit announcer
- Last Active Nov 9th 2022

merging some information from the articles on equality and natural deduction into its own article about conversion rules.

Anonymous

- Discussion Type
- discussion topicinductive definition
- Category Latest Changes
- Started by nLab edit announcer
- Comments 1
- Last comment by nLab edit announcer
- Last Active Nov 9th 2022

- Discussion Type
- discussion topicVeneziano amplitude
- Category Latest Changes
- Started by nLab edit announcer
- Comments 1
- Last comment by nLab edit announcer
- Last Active Nov 8th 2022

- Discussion Type
- discussion topicOka principle
- Category Latest Changes
- Started by Urs
- Comments 10
- Last comment by nLab edit announcer
- Last Active Nov 8th 2022

added publication data to:

- Finnur Lárusson,
*Model structures and the Oka principle*, Journal of Pure and Applied Algebra Volume 192, Issues 1–3, 1 September 2004, Pages 203-223 (math.CV/0303355, doi:10.1016/j.jpaa.2004.02.005)

- Finnur Lárusson,

- Discussion Type
- discussion topicplethysm
- Category Latest Changes
- Started by nLab edit announcer
- Comments 1
- Last comment by nLab edit announcer
- Last Active Nov 8th 2022

- Discussion Type
- discussion topic2-plethory
- Category Latest Changes
- Started by nLab edit announcer
- Comments 1
- Last comment by nLab edit announcer
- Last Active Nov 8th 2022

- Discussion Type
- discussion topicMiklos Rédei
- Category Latest Changes
- Started by Urs
- Comments 1
- Last comment by Urs
- Last Active Nov 8th 2022

- Discussion Type
- discussion topicHilbert space
- Category Latest Changes
- Started by Urs
- Comments 19
- Last comment by Urs
- Last Active Nov 8th 2022

there had been no references at

*Hilbert space*, I have added the following, focusing on the origin and application in quantum mechanics:John von Neumann,

*Mathematische Grundlagen der Quantenmechanik*. (German) Mathematical Foundations of Quantum Mechanics. Berlin, Germany: Springer Verlag, 1932.George Mackey,

*The Mathematical Foundations of Quamtum Mechanics*A Lecture-note Volume, ser. The mathematical physics monograph series. Princeton university, 1963E. Prugovecki,

*Quantum mechanics in Hilbert Space*. Academic Press, 1971.

- Discussion Type
- discussion topicequality
- Category Latest Changes
- Started by Urs
- Comments 59
- Last comment by nLab edit announcer
- Last Active Nov 8th 2022

I was involved in some discussion about where the word “intensional” as in “intensional equality” comes from and how it really differs from “intenTional” and what the point is of having such a trap of terms.

Somebody dug out Martin-Löf’s lecture notes “Intuitionistic type theory” from 1980 to check. Having it in front of me and so before I forget, I have now briefly made a note on some aspects at

*equality*in the section*Different kinds of equalits*(below the first paragraph which was there before I arrived.)Anyway, on p. 31 Martin-Löf has

intensional (sameness of meaning)

I have to say that the difference between “sameness of meaning” and “sameness of intenTion”, if that really is the difference one wants to make, is at best subtle.

- Discussion Type
- discussion topiclogic symbols -- table
- Category Latest Changes
- Started by Urs
- Comments 8
- Last comment by nLab edit announcer
- Last Active Nov 8th 2022

- Discussion Type
- discussion topicstate monad
- Category Latest Changes
- Started by Urs
- Comments 5
- Last comment by Urs
- Last Active Nov 8th 2022

started a bare minimum at

*state monad*

- Discussion Type
- discussion topicquantum IO monad
- Category Latest Changes
- Started by Urs
- Comments 1
- Last comment by Urs
- Last Active Nov 8th 2022

- Discussion Type
- discussion topiclinear implication
- Category Latest Changes
- Started by Urs
- Comments 1
- Last comment by Urs
- Last Active Nov 8th 2022

- Discussion Type
- discussion topicNesta van der Schaaf
- Category Latest Changes
- Started by Urs
- Comments 1
- Last comment by Urs
- Last Active Nov 8th 2022

- Discussion Type
- discussion topictwisted de Rham cohomology
- Category Latest Changes
- Started by Urs
- Comments 16
- Last comment by Urs
- Last Active Nov 8th 2022

added pointer to the original article:

- Ryan Rohm, Edward Witten, around (23) and appendix of:
*The antisymmetric tensor field in superstring theory*, Annals of Physics Volume 170, Issue 2, September 1986, Pages 454-489 (doi:10.1016/0003-4916(86)90099-0)

- Ryan Rohm, Edward Witten, around (23) and appendix of:

- Discussion Type
- discussion topicassignment operator
- Category Latest Changes
- Started by nLab edit announcer
- Comments 9
- Last comment by nLab edit announcer
- Last Active Nov 8th 2022

- Discussion Type
- discussion topicproperad
- Category Latest Changes
- Started by Dmitri Pavlov
- Comments 13
- Last comment by David_Corfield
- Last Active Nov 7th 2022

I created the article properad, essentially a brief description of the definition together with a reference.

- Discussion Type
- discussion topicLie algebra extension
- Category Latest Changes
- Started by Urs
- Comments 2
- Last comment by nLab edit announcer
- Last Active Nov 7th 2022

The entry

*Lie algebra extension*used to have only a discussion of the fairly exotic topic of classification in nonabelian Lie algebra cohomology. I have now added an Idea-section with some more introductory and more traditional remarks. This could well be expanded much further.

- Discussion Type
- discussion topicFrobenius monad
- Category Latest Changes
- Started by Urs
- Comments 2
- Last comment by Urs
- Last Active Nov 7th 2022

- Discussion Type
- discussion topicadditive disjunction
- Category Latest Changes
- Started by Urs
- Comments 1
- Last comment by Urs
- Last Active Nov 7th 2022

- Discussion Type
- discussion topicquantum information theory via dagger-compact categories
- Category Latest Changes
- Started by Urs
- Comments 9
- Last comment by David_Corfield
- Last Active Nov 7th 2022

the entry that used to be titled

*quantum mechanics in terms of dagger-compact categories*I have renamed into*finite quantum mechanics in terms of dagger-compact categories*(with a “finite” up front) and I have added to the first sentence the qualifier “finite” and “finite-dimensional” a bunch of times.I am currently at “Quantum Physics and Logic 2012” in Brussels, and every second speaker advertizes the formalism of what they call “categorical quantum theory”. It’s all fine for the majority of the audience which is all into

*quantum information*theory, where one is only interested in shuffling a finite bunch of qbits around, but it is rather misleading from an ordinary perspective on quantum physics. Already the particle on the line is not a finite quantum system.

- Discussion Type
- discussion topicepsilon-number
- Category Latest Changes
- Started by Mike Shulman
- Comments 3
- Last comment by Urs
- Last Active Nov 7th 2022

Created ε-number.

- Discussion Type
- discussion topictensor product of abelian groups
- Category Latest Changes
- Started by Urs
- Comments 9
- Last comment by nLab edit announcer
- Last Active Nov 7th 2022

have split off

*tensor product of abelian groups*from*tensor product*and expanded slightly

- Discussion Type
- discussion topicZX-calculus
- Category Latest Changes
- Started by Urs
- Comments 1
- Last comment by Urs
- Last Active Nov 7th 2022

- Discussion Type
- discussion topicquantum information theory via string diagrams -- references
- Category Latest Changes
- Started by Urs
- Comments 1
- Last comment by Urs
- Last Active Nov 7th 2022

splitting off and expanding this list of references from

*quantum information theory via dagger-compact categories*, to be re-`!include`

d there and elsewhere, for ease of syncing

- Discussion Type
- discussion topicgaunt category
- Category Latest Changes
- Started by Mike Shulman
- Comments 15
- Last comment by nLab edit announcer
- Last Active Nov 6th 2022

- Discussion Type
- discussion topicsplit coequalizer
- Category Latest Changes
- Started by FinnLawler
- Comments 6
- Last comment by Guest
- Last Active Nov 6th 2022

The page split coequalizer said that the canonical presentation of an Eilenberg–Moore algebra is a split coequalizer in the category of algebras. I don’t think that’s right – if I recall correctly it’s reflexive there, but in general not split until you forget down to the underlying category. So I changed the page.

- Discussion Type
- discussion topiccomputational trilogy
- Category Latest Changes
- Started by Urs
- Comments 58
- Last comment by David_Corfield
- Last Active Nov 6th 2022

created

*computational trinitarianism*, combining a pointer to an exposition by Bob Harper (thanks to David Corfield) with my table logic/category-theory/type-theory.

- Discussion Type
- discussion topiccomparison functor
- Category Latest Changes
- Started by Urs
- Comments 1
- Last comment by Urs
- Last Active Nov 6th 2022

A dedicated discussion of the comparison maps between any adjunction and its initial Kleisli- and terminal monadic adjunction is being alluded to in various related entries, but none of them has really been admitting to details or giving any concrete citations.

This entry is meant to fill that gap. It’s unfortunate that this important concept does not have a more descriptive name. I have added some words of disambiguation in order to account for this.

- Discussion Type
- discussion topicmonadic functor
- Category Latest Changes
- Started by Alec Rhea
- Comments 8
- Last comment by Urs
- Last Active Nov 6th 2022

The link for ’equivalent’ at the top redirected to natural isomorphism which (as I understand it) is the correct 1-categorical version of an equivalence of functors, but this initially lead me to believe that a functor was monadic iff it was naturally isomorphic to a forgetful functor from the Eilenberg-Moore category of a monad on its codomain, which would mean that the domain of the functor was literally the Eilenberg-Moore category of some adjunction since natural isomorphism is only defined for parallel functors.

- Discussion Type
- discussion topiccreated limit
- Category Latest Changes
- Started by Urs
- Comments 3
- Last comment by nLab edit announcer
- Last Active Nov 6th 2022

- Discussion Type
- discussion topiccountable choice
- Category Latest Changes
- Started by DavidRoberts
- Comments 1
- Last comment by DavidRoberts
- Last Active Nov 5th 2022

- Discussion Type
- discussion topicpresentation axiom
- Category Latest Changes
- Started by Todd_Trimble
- Comments 8
- Last comment by DavidRoberts
- Last Active Nov 5th 2022

A number of examples and counterexamples have been firmed up at presentation axiom. Some of them devolve on an observation made by Jonas Frey a few days ago at internally projective object, for which I added a simple proof. There are still some points that needed to be clarified regarding the internalization of the presentation axiom, but for now the discussion is concentrated on relations between externally projeective and internally projective objects.

- Discussion Type
- discussion topicextension system
- Category Latest Changes
- Started by Mike Shulman
- Comments 8
- Last comment by Urs
- Last Active Nov 5th 2022

Created extension system.

- Discussion Type
- discussion topicKleisli triple
- Category Latest Changes
- Started by Urs
- Comments 1
- Last comment by Urs
- Last Active Nov 5th 2022

- Discussion Type
- discussion topicincompleteness theorem
- Category Latest Changes
- Started by Urs
- Comments 1
- Last comment by Urs
- Last Active Nov 5th 2022

added publication details for:

- Russell O’Connor,
*Essential Incompleteness of Arithmetic Verified by Coq*, in:*Theorem Proving in Higher Order Logics. TPHOLs 2005*, Lecture Notes in Computer Science**3603**, Springer (2005) 245-260 [web, arXiv:cs/0505034, doi:10.1007/11541868_16]

- Russell O’Connor,

- Discussion Type
- discussion topicdatabase
- Category Latest Changes
- Started by Urs
- Comments 1
- Last comment by Urs
- Last Active Nov 5th 2022

- Discussion Type
- discussion topicalgebra over a monad
- Category Latest Changes
- Started by Richard Williamson
- Comments 17
- Last comment by Urs
- Last Active Nov 5th 2022

- Discussion Type
- discussion topiccoalgebra over a comonad
- Category Latest Changes
- Started by Urs
- Comments 1
- Last comment by Urs
- Last Active Nov 5th 2022

- Discussion Type
- discussion topiclens (in computer science)
- Category Latest Changes
- Started by David_Corfield
- Comments 51
- Last comment by Urs
- Last Active Nov 5th 2022

- Discussion Type
- discussion topicFormal Moduli Problems and DG-Lie Algebras
- Category Latest Changes
- Started by nLab edit announcer
- Comments 1
- Last comment by nLab edit announcer
- Last Active Nov 5th 2022

- Discussion Type
- discussion topicStiefel-Whitney class
- Category Latest Changes
- Started by Urs
- Comments 7
- Last comment by nLab edit announcer
- Last Active Nov 5th 2022

added to Stiefel-Whitney class briefly the definition/characterization.

- Discussion Type
- discussion topicweak topology
- Category Latest Changes
- Started by Urs
- Comments 1
- Last comment by Urs
- Last Active Nov 4th 2022

There seems to have remained a typo in the definition (here) of the strong/fine/final topology (probably induced from copy-and-pasting the previous definition of the weak/coarse/initial topology and not adjusting appropriately at all instances): It had the intersection instead of the union of all candidate topologies. I have fixed it (I believe) and have created separate subsections for the two notions.

- Discussion Type
- discussion topicnatural deduction
- Category Latest Changes
- Started by nLab edit announcer
- Comments 9
- Last comment by eonmorgan
- Last Active Nov 4th 2022

- Discussion Type
- discussion topicpointed type
- Category Latest Changes
- Started by nLab edit announcer
- Comments 1
- Last comment by nLab edit announcer
- Last Active Nov 4th 2022

- Discussion Type
- discussion topicGabriel's theorem
- Category Latest Changes
- Started by Urs
- Comments 4
- Last comment by nLab edit announcer
- Last Active Nov 4th 2022

- Discussion Type
- discussion topicStarobinsky model of cosmic inflation
- Category Latest Changes
- Started by Urs
- Comments 21
- Last comment by Urs
- Last Active Nov 4th 2022

- Discussion Type
- discussion topicp-adic string theory
- Category Latest Changes
- Started by Urs
- Comments 10
- Last comment by Urs
- Last Active Nov 4th 2022

Preprint today by Yau et al., relating $p$-adic strings to the Riemann zeta function:

- An Huang, Bogdan Stoica, Shing-Tung Yau,
*General relativity from $p$-adic strings*(arXiv:1901.02013)

- An Huang, Bogdan Stoica, Shing-Tung Yau,

- Discussion Type
- discussion topicdisjunction
- Category Latest Changes
- Started by David_Corfield
- Comments 4
- Last comment by nLab edit announcer
- Last Active Nov 3rd 2022

- Discussion Type
- discussion topicterm elimination
- Category Latest Changes
- Started by nLab edit announcer
- Comments 1
- Last comment by nLab edit announcer
- Last Active Nov 3rd 2022

- Discussion Type
- discussion topichypergeometric function
- Category Latest Changes
- Started by Urs
- Comments 2
- Last comment by zskoda
- Last Active Nov 3rd 2022

- Discussion Type
- discussion topicdivergent series
- Category Latest Changes
- Started by zskoda
- Comments 4
- Last comment by zskoda
- Last Active Nov 3rd 2022

I recorded several references at a newly created stub divergent series.

- Discussion Type
- discussion topicrack
- Category Latest Changes
- Started by Todd_Trimble
- Comments 6
- Last comment by zskoda
- Last Active Nov 3rd 2022

Over at rack, I noticed brief mention of the notion of shelf. As some of you will know, shelves also crop up in large cardinal axioms, so I gave shelf its own subsection and mentioned some of the lore (e.g., Laver tables). The topic might be worth a separate page.

- Discussion Type
- discussion topicrule C
- Category Latest Changes
- Started by zskoda
- Comments 3
- Last comment by zskoda
- Last Active Nov 3rd 2022