Skip to main content
Search type Search syntax
Tags [tag]
Exact "words here"
Author user:1234
user:me (yours)
Score score:3 (3+)
score:0 (none)
Answers answers:3 (3+)
answers:0 (none)
isaccepted:yes
hasaccepted:no
inquestion:1234
Views views:250
Code code:"if (foo != bar)"
Sections title:apples
body:"apples oranges"
URL url:"*.example.com"
Saves in:saves
Status closed:yes
duplicate:no
migrated:no
wiki:no
Types is:question
is:answer
Exclude -[tag]
-apples
For more details on advanced search visit our help page
Results tagged with
Search options questions only not deleted user 28128

Nonstandard analysis is a way of doing calculus and analysis with infinitesimals. The historical approach of Leibniz, Euler, and others to infinitesimal calculus was gradually replaced by epsilon, delta techniques in the context of a real continuum, in the 19th century. It was not until the 1960s that Abraham Robinson developed a theory of a hyperreal continuum that allows for a development of analysis procedurally akin to that of its founders.

1 vote
0 answers
158 views

Embedding standard function spaces into superstructure

I have a question concerning the precise handling the usual function spaces like $L^2$ in the context of the superstructure. In their paper Benci, Vieri; Luperi Baglini, Lorenzo. Generalized solut …
Mikhail Katz's user avatar
  • 16.6k
6 votes
1 answer
727 views

Did Bishop make those comments in his oral presentation?

The 1975 published version of a 1974 talk at a workshop by Errett Bishop contains the following comment: "A more recent attempt at mathematics by formal finesse is non-standard analysis. I gather …
Mikhail Katz's user avatar
  • 16.6k
17 votes
1 answer
2k views

Did Lagrange change his mind about infinitesimals?

Lagrange is famous for his attempt to found analysis algebraically using power series expansions, an approach that, as we know today, is limited to analytic functions. Lagrange is also known as the in …
Mikhail Katz's user avatar
  • 16.6k
8 votes
2 answers
2k views

Which universities teach true infinitesimal calculus? [closed]

My colleague and I are currently teaching "true infinitesimal calculus" (TIC), in the sense of calculus with infinitesimals, to a class of about 120 freshmen at our university, based on the book by Ke …
8 votes
1 answer
708 views

Who said "the naive counting numbers don't exhaust $\Bbb N$"?

In the context of Robinson's framework, or more precisely its reformulation by Ed Nelson, one of the practitioners in the field expressed the sentiment something like "the naive counting numbers don't …
Mikhail Katz's user avatar
  • 16.6k
3 votes
3 answers
786 views

Lapses of "the early proponents of the doctrine of limits"

I have a question that I have been wondering about for a long time without finding any answer. Concerning the period around 1900, Robinson commented in his 1966 book that "there is in the writings of …
Mikhail Katz's user avatar
  • 16.6k
4 votes
1 answer
437 views

Paris-Harrington via overspill?

I saw in an old logic paper that the Paris-Harrington theorem can be proved via Overspill. The presentation is unfortunately too technical for me to follow. Does somebody have any insight into this? …
Mikhail Katz's user avatar
  • 16.6k
2 votes
0 answers
264 views

Comparison of model-theoretic and axiomatic approaches to NSA

This question is motivated by the discussion in the comments to this post. The question concerns a comparison of model-theoretic (extension) approaches to nonstandard analysis, and axiomatic (syntact …
Mikhail Katz's user avatar
  • 16.6k
9 votes
2 answers
917 views

differential geometry using Robinson's infinitesimals?

Is there a detailed treatment of differential geometry using Robinson's infinitesimals?
Mikhail Katz's user avatar
  • 16.6k
7 votes
3 answers
5k views

Was Cauchy prescient?

Cauchy proved a sum theorem for series of continuous functions in 1821, and published another article on the subject in 1853. Michael Segre, writing in Archive for History of Exact Sciences, claimed …
6 votes
1 answer
350 views

Quantifier complexity of definition of compactness

This question is inspired by the post on quantifier complexity of continuity. We work with metric spaces M considered as two-sorted first-order structures (M,$\mathbb R$,d,+,⋅,<) where $d:M^2→\mathbb …
Mikhail Katz's user avatar
  • 16.6k
21 votes
9 answers
5k views

Was the early calculus inconsistent?

This question does NOT concern the RIGOR, or lack thereof, of the early calculus. Rather the question is of its CONSISTENCY. George Berkeley wrote in 1734 with reference to the early calculus that s …
Mikhail Katz's user avatar
  • 16.6k
2 votes
1 answer
313 views

Is there a model of ZF+ACC where transfer fails for the definable hyperreals?

In 2003 Kanovei and Shelah constructed a definable hyperreal field. The ultrapower used exploits a fairly large index set so that it is clear that the usual proof of Los and transfer does not go throu …
Mikhail Katz's user avatar
  • 16.6k
3 votes
0 answers
473 views

Deducing Skolem's nonstandard integers from downward Lowenheim-Skolem?

If one has a nonstandard model $\mathcal{N}$ of PA and adjoins to the first-order theory the countable list of axioms $1<H,\, 2<H,\, 3<H, \ldots$ (satisfied in $\mathcal{N}$) for all the "standard" na …
Mikhail Katz's user avatar
  • 16.6k
5 votes
2 answers
486 views

How is compactness related to countable saturation?

By Cantor's intersection theorem every decreasing nested sequence of nonempty compact sets has a common point. A superficially similar result holds that every decreasing nested sequence of nonempty …
Mikhail Katz's user avatar
  • 16.6k

15 30 50 per page