Throughout:Changes made July 2002:VennFAQ.html :
- Updated anchor format to be more compatible with browsers.
- corrected knot/link terminology.
- corrected typos pointed out by Edwards, Hamburger, and others (including ourselves).
- Updated all the headers to be consistent (updated Meta tags).
- deleted VennMinEJC.html, as its content is already incorporated in several other pages, and it is not linked in with the rest of the site.
- updated file structure list in this page.
- made math notation nicer throughout: eg. put π (& pi;) instead of pi... (many minor tweaks, nothing major)
- Added new page VennSeparatedEJC.html, to explicate example of separating vertices to make simple symmetric 5-Venn diagram. Linked to it from VennGraphEJC.html and VennNecklaceEJC.html
- Updated and fixed all broken and redirected links, references, etc.
- Updated authors, copyright dates, version numbers, throughout. Took Frank's old email address out of headers.
VennAckEJC.html :
- Added question on copyrights.
- Added information and figure on "viscera piscis" to question on name of intersecting region. Thanks to Stuart Anderson for the information and figure.
- Added information on Stirling Chow's DrawEuler and DrawVenn programs.
VennJohnEJC.html :
- Added new paragraph of acknowledgements for the update.
VennEJC.html :
- Added reference to Edwards' book.
- Added sentence indicating Venn's role in Venn diagram history.
VennGraphEJC.html :
- Changed first sentence from "combinatorial properties" to "combinatorial and geometric properties".
- Added links to subsub pages, for easy navigation.
- Removed mention of Hamburger's survey, as it has not been published and is hard to get a hold of.
- Removed caveat about current browsers and a colour monitor - we can probably assume this is not a problem these days.
- Updated authors list.
- Added automatic instant redirect so that the first page seen is VennEJC.html, to make it consistent with the rest of the pages (which refer to VennEJC.html as the root page).
- Updated section headings under each page listing. Made them consistent from page to page as to what is listed and what isn't.
- Minor wording changes.
VennOpenEJC.html :
- Added figures of two simple 4-Venn diagrams.
- Added reference to Kn.
- Changed terminology: dual graph is now called "Venn dual" (D(C)), not "Venn graph", to be consistent and clearer throughout.
- Slightly formalized section on splitting vertices.
- Updated section on congruent Venn diagrams to include figure from HP97, and better references to other figures.
- Updated section on minimum Venn diagrams to refer to GKS, BGR, and gave proper credit to diagrams.
- Clarified the origin of radual graph.
- Updated Carroll's remarks to clarify that he did an exhaustive search of simple diagrams.
- Fixed some typos noticed by Hamburger.
- Added footnote defining "Tutte embedding".
- Added cross-referencing between "revolving door lists" section and Gray codes section on Symmetric Venn Diagrams page.
- Updated minimum vertex section to refer to existence of minimum-vertex 7s. Linked to appropriate section on symmetry page, and cleaned up formatting.
- Added a bit in the first section to indicate that we can label the vertices in the Venn dual graph with bitstrings.
- Updated final section with new 5-ellipse figures, altered text to match.
VennOtherEJC.html (and VennGeometricEJC.html):
- Added k-gons problem, polyominoes problem, Generalizations section.
- Added complexity problem, polar symmetric 11 problem, cleaned up problem about minimum-area diagrams, cleaned up problem about spanning subgraphs of the hypercube.
- Removed open problem regarding existence of symmetric 13-VD, answered in the affirmative by GKS.
- In preparation for adding lots of new open problems, split the list into "geometric" and "combinatorial" open problems, as there seems to be a very natural division between the two sets.
VennRefs.html :
- Added Carroll's proof.
- Euler diagrams: clarified that Euler didn't mention the 3-circle diagram (as far as we can tell). Added example of impossible set system.
- Took out mention of Grünbaum's Theorem on K(n) as it is superseded by the table under Lemma G.
- Added link to simple 7-Venn diagram of quadrilaterals we found.
- Added new page for poly-Venn diagrams for 6 and 7 curves in CR04.
- Clarified reference to iEuler diagrams.
- Added reference to RRS+Gr75 in connection with existence of convex diagrams for every n.
- Added link to k-fold 2-Venn diagram page. Corrected error in title of k-fold 2-Venn diagram page (it erroneously said they were "2-fold Venn diagrams" when they are k-fold 2-Venn diagrams, with various k).
- Added bit about Venn-Pierce diagrams and link to Shin's book.
- Page getting very long, so split into two pages, one dealing with geometric aspects. Added new introductions to each page.
- Put in discussion and table of minimum k required for simple diagram of k-gons.
- Put in Frank and Stirling's Venn polyominoes stuff under "Area-proportional" stuff, with a separate smaller heading, as in a sense these are "minimum area" diagrams.
- Split the page into sections with section headings.
- Added subsection on "Generalizations of Symmetric Diagrams" under "Geometrical variants", containing the symmetric independent families and near-Venn diagram stuff from RW, including mention of Jiang's thesis results.
- Moved the (very short) section called "More Ellipses" to the "Venn diagrams made from congruent curves" section in VennGraphEJC.html, as it seems out of place in VennOtherEJC, and is sort of related to the rest of the material in the section in VennGraphEJC.
- Put in section for area-proportional stuff.
- Pasted VennEulerEJC.html page into a section on this page.
VennSymmEJC.html and VennNecklace.html :
- Added some obscure references.
- Added Jo, CR98, Kn, KM, GHKT, Edward's note in Obscure References on the Venn diagram window.
- Removed CHP97a, which was an accidental duplicate of HP97. Updated appearances in text to reflect this.
- Added Andrew Glassner's paper.
- Added new references suggested by Hamburger, and updated manuscript for "Pretty Drawings".
- Added Tutte's paper How to draw a graph.
- Added corrections suggested by Carla Savage.
- Added Shin's book.
- Added paper at the end of Edwards' book, "Metrical Venn diagrams".
- Added Frank and Stirling's "minimum area Venn diagrams" manuscript.
- Added EZ, paper on incremental construction algorithm. Update: took it back out again as the paper doesn't prove correctness, and the examples given are flawed (have repeated regions).
- Added Hamburger's "Pretty drawings" manuscript.
- Added reference to Jeremy Carroll's technical report, Car00, and changed other reference to Car99 (Car00 doesn't replace it as Car99 is cited in connection with something that isn't mentioned in Car00).
- Added reference to CR, area-proportional paper.
- Added references to Hamburger's (many) papers 2000-2004.
- Added references to three recent MSc theses relevant to symmetric Venn diagrams: [Wes], [Ca], and [Ji].
- Updated reference to Hamburger's manuscript in 2000 to published version. Changed reference from [Ha01] to [Ha02] in VennSymmEJC.html.
- Updated reference to Hamburger+Pippert's manuscript in 1996 to published version. Changed reference from [HP96c] to [HP97] throughout.
- Added references to GKS, KillianRuskeySavageWeston, Ruskey and Weston, and Edwards' book.
- Added reference to MC.
- Corrected a few minor typos in the references page.
- Added reference to Greene/Kleitman paper.
VennWhatEJC.html :
- Added reference to KM.
- Added separate page for the example diagram not constructable from sectors of necklaces.
- Added reference to Johnson paper in discussion on middle two levels problem.
- Added clearer reference to Min7 page.
- Mentioned logo.
- Cleared up description of polar symmetry.
- Changed table in Construction section to be a "best known" table, with references.
- Clarified references to He and Ed96 in He's proof; added reference to Ha02 in discussion of GKS result.
- Split symmetric page into three pages as it was getting far too long.
- Added discussion of new 11-Venn diagrams in Hamburger's recent papers.
- Added Tutte embedding of the 5; reorganized the initial few paragraphs of n=5 section to better present different versions of the n=5 diagram.
- Renamed initial section from "Symmetric Venn Diagrams" to "Rotational Symmetry".
- Put Min7NonPolar.html and Min7Polar.html on same page (with anchors) and fixed up format and links to them. Changed the figures so they are all (about) the same size.
- Added information about Hamburger et al.'s 1837-vertex diagram.
- Added blurb about signed Gauss codes in Grünbaum encoding section.
- Fixed error in Min7Polar.html figure: one curve incorrectly coloured in top figure.
- Added new 5-ellipse figure, changed text to match.
- Added symmetric 5 equilateral triangles figure (linked to it from beginning of n=5 section).
- Removed mention of G-encoding, as this usage conflicts with Tao Cao's thesis. Since the encoding is the one used in nonsymm7.txt and NonMonotoneEJC.html , added a brief description of the encoding (renamed to RG-encoding, to avoid conflict) into nonsymm7.txt and a line pointing to that file in NonMonotoneEJC.html.
- Changed section on "middle two levels problem" so that it doesn't refer wistfully to a construction for symmetric Venn diagrams in general, as now we have one.
- Added section on pseudo-symmetry and figures.
- Split VennNecklace.html into two sections and put section headings at the top.
- Added Hamburger and Pippert's min-vertex diagram to n=7 section.
- Added figures and brief discussion of GKS's 11-VD in n=11 section.
- Minor updates in the first section to refer to GKS result.
- Minor updates in n=11 section to clarify that Hamburger's was the first 11.
- Added new section called "A Construction for Symmetric Venn Diagrams" to explain GKS result.
- Added details on GKS construction to VennNecklaceEJC.html, including a new figure.
- Added new section for Pseudo-symmetry, called "Symmetric Diagrams for Non-Prime n"
- Added reference to Henderson for the proof that n must be prime, at beginning of page.
- Added Hamburger's minimum-vertex symmetric 7-Venn diagram and some discussion of it to section on 7s.
- Added mention of generation results of rigid monotone 7-symmetric diagrams from [Wes] into section on non-simple 7s. Also added link to picture of polar symmetric monotone 7-VD with minimum number of vertices for monotone 7s.
- Added reference to Cao at the end of section on Grünbaum encodings.
- Added references to some other, mostly earlier, constructions of Venn diagrams.
- Added mention of using Venn diagrams for logical purposes, and references.
- Added Venn's 4 ellipses example.
- Added two sectional anchors and changed format a bit to make it consistent with other pages.
- Added a few sentences to definitions of "simple" to make it stand out a bit more.
- Added short paragraph explaining there are exactly 2^{n} regions, and distinguishing between Venn and Euler diagrams, with link to VennOtherEJC.html#euler for more information.
This was a major updating, in preparation for a new version to appear as an on-line survey in the ElJC. Not all changes are outlined below.