- From: Joe Gittings <joe.gittings@ucl.ac.uk>
- Date: Thu, 14 Jun 2001 16:10:22 +0100
- To: Irene Vatton <Irene.Vatton@inrialpes.fr>
- CC: www-amaya <www-amaya@w3.org>
Thanks for the response. A few thoughts: i) As the developer this is very obvious to you. But as a user, it was completely non-obvious! I had absolutely no way of knowing that I should hit Esc. All I could see was that Amaya wasn't deleting what I asked it to. At the very least, it would be a good idea for Amaya to display an informative messsage box in this situation. ii) I don't believe I was trying to do anything unreasonable in this situation. I wanted to delete a particular block of text, and Amaya wouldn't let me. Hitting Esc means I end up deleting more than I want to. If Amaya is a WYSIWYG editor, surely there shouldn't be such a concept as an "inconsistent selection", as this is forcing users to take account of the underlying HTML/MathML. iii) If I enlarge the selection, delete it, and then Undo the deletion, I can then delete the area I originally wanted to delete. This suggests to me that it should have been possible to delete that area in the first place... Sorry to be a pain, but I am using Amaya a lot, and am just putting the user's point of view! Joe Irene Vatton wrote: > It's just due to an inconsistent selection in the tree structure. > You have to hit the key Escape (F2 on windows) to request Amaya to > generate the corresponding consistent selection then you will be able > to remove it. > > > Hi, > > > > I'd like to report this bug, which I've been observing occasionally. > > Sometimes, it is not possible to delete a selected region containing > > MathML. I attach an example. The problem appears to depend on the > > relationship between the undeletable region and the rest of the > > document. > > > > I say this because in the case of this example, if one copies and pastes > > the undeletable region into a new blank document, it is possible to > > delete it in the new document. So its undeletability appears to be > > connected with other parts of the document. Furthermore, other regions > > of this example document are deletable. Also, slightly changing the > > extent of the selected region makes it deletable. Thus I attach the > > entire document, rather than just the undeletable region. > > > > OK here is the example. Open the attachment in Amaya and select the > > region between: > > "Bell states:" > > and > > "If <lambda> is unknown, the probability distribution" > > *inclusive*. > > > > You should find that hitting backspace or delete or selecting the Delete > > menu item has no effect. If I enlarge the extent of the selection, say > > to include sections 4.1.1, 4.1.2, and 4.1.5, I can delete it fine. > > > > This problem has been a nuisance for me before, as it has resulted in me > > having to delete more than I want to in order to delete something! > > > > Thanks, > > Joe > > > > > > > > <?xml version="1.0" encoding="iso-8859-1"?> > > <html xmlns="http://www.w3.org/1999/xhtml"> > > <head> > > <title>Preskill Chap 4 notes</title> > > <meta name="GENERATOR" content="amaya V4.3.2" /> > > <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" /> > > </head> > > > > <body> > > <h1>Notes on Preskill chapter 4</h1> > > > > <p>Joe Gittings</p> > > > > <p>June 2001</p> > > > > <p></p> > > > > <h2>4.1.1 Hidden quantum information</h2> > > > > <p>Bell states:</p> > > > > <p>| > > <math xmlns="http://www.w3.org/1998/Math/MathML"> > > <msup> > > <mi>Φ</mi> > > <mo>1</mo> > > </msup> > > </math> > > ⟩ = > > <math xmlns="http://www.w3.org/1998/Math/MathML"> > > <mfrac> > > <mn>1</mn> > > <mrow> > > <mo>√</mo> > > <mn>2</mn> > > </mrow> > > </mfrac> > > </math> > > (|00⟩1|11⟩ )</p> > > > > <p>| > > <math xmlns="http://www.w3.org/1998/Math/MathML"> > > <msup> > > <mi>ψ</mi> > > <mo>1</mo> > > </msup> > > </math> > > ⟩ = > > <math xmlns="http://www.w3.org/1998/Math/MathML"> > > <mfrac> > > <mn>1</mn> > > <mrow> > > <mo>√</mo> > > <mn>2</mn> > > </mrow> > > </mfrac> > > </math> > > (|01⟩1|10⟩)</p> > > > > <p></p> > > > > <h2>4.1.2 Einstein locality and hidden variables</h2> > > > > <p><span style="text-decoration: underline">Hidden-variable theory result for > > measuring the pure state</span><span > > style="text-decoration: underline">|</span> > > <math xmlns="http://www.w3.org/1998/Math/MathML" > > style="text-decoration: underline"> > > <msub> > > <mo>↑</mo> > > <mi>z</mi> > > </msub> > > </math> > > <span style="text-decoration: underline">⟩</span><span > > style="text-decoration: underline">along axis rotated by</span><span > > style="text-decoration: underline">θ</span><span > > style="text-decoration: underline">from z</span>:</p> > > > > <p>If we assume | > > <math xmlns="http://www.w3.org/1998/Math/MathML"> > > <msub> > > <mo>↑</mo> > > <mi>z</mi> > > </msub> > > </math> > > ⟩ is in fact parameterized by (z,λ) where 0 ≤ λ ≤ 1 > > is the hidden variable, the outcome is:</p> > > > > <p>| > > <math xmlns="http://www.w3.org/1998/Math/MathML"> > > <msub> > > <mo>↑</mo> > > <mi>θ</mi> > > </msub> > > </math> > > ⟩ for 0 ≤ λ ≤ > > <math xmlns="http://www.w3.org/1998/Math/MathML"> > > <msup> > > <mi>cos</mi> > > <mn>2</mn> > > </msup> > > <mfrac> > > <mi>θ</mi> > > <mn>2</mn> > > </mfrac> > > </math> > > </p> > > > > <p>| > > <math xmlns="http://www.w3.org/1998/Math/MathML"> > > <msub> > > <mo>↓</mo> > > <mi>θ</mi> > > </msub> > > </math> > > ⟩ for cos > > <math xmlns="http://www.w3.org/1998/Math/MathML"> > > <msup> > > <mn>2</mn> > > </msup> > > <mfrac> > > <mi>θ</mi> > > <mn>2</mn> > > </mfrac> > > <mo></mo> > > <mo></mo> > > <mo><</mo> > > <mi>λ</mi> > > <mo>≤</mo> > > <mo>1</mo> > > </math> > > </p> > > > > <p>If λ is unknown, the probability distribution for the measurement > > agrees with quantum theory.</p> > > > > <p></p> > > > > <h2>4.1.5 More Bell inequalities</h2> > > > > <p></p> > > > > <p><span style="text-decoration: underline">Most general statement of Bell > > inequality</span>:</p> > > > > <p>For two photons whose polarizations are correlated in the state | > > <math xmlns="http://www.w3.org/1998/Math/MathML"> > > <msup> > > <mi>Φ</mi> > > <mo>+</mo> > > </msup> > > </math> > > ⟩:</p> > > > > <p>|⟨<strong>ab</strong>⟩ - ⟨<strong>ac</strong>⟩| ≤ 1 > > - ⟨<strong>bc</strong>⟩ is violated</p> > > > > <p>where the observables are</p> > > > > <p><strong>a</strong> = > > <math xmlns="http://www.w3.org/1998/Math/MathML"> > > <msup> > > <mi>τ</mi> > > <mrow> > > <mo>(</mo> > > <mi>A</mi> > > <mo>)</mo> > > </mrow> > > </msup> > > </math> > > (α)</p> > > > > <p><strong>b</strong> = > > <math xmlns="http://www.w3.org/1998/Math/MathML"> > > <msup> > > <mi>τ</mi> > > <mrow> > > <mo>(</mo> > > <mi>B</mi> > > <mo>)</mo> > > </mrow> > > </msup> > > </math> > > (β)</p> > > > > <p><strong>c</strong>= > > <math xmlns="http://www.w3.org/1998/Math/MathML"> > > <msup> > > <mi>τ</mi> > > <mrow> > > <mo>(</mo> > > <mi>A</mi> > > <mo>)</mo> > > </mrow> > > </msup> > > </math> > > (γ) = > > <math xmlns="http://www.w3.org/1998/Math/MathML"> > > <msup> > > <mi>τ</mi> > > <mrow> > > <mo>(</mo> > > <mi>B</mi> > > <mo>)</mo> > > </mrow> > > </msup> > > </math> > > (γ)</p> > > > > <p>and <strong>τ</strong>(θ) is the polarization operator with > > eigenvalues 11</p> > > > > <p>i.e. <strong>a</strong> is the polarization of photon A measured along the > > axis α.</p> > > > > <p></p> > > > > <p><span style="text-decoration: underline">CHSH (Clauser-Horne-Shimony-Holt) > > inequality</span>:</p> > > > > <p>|⟨<strong>ab</strong>⟩ +⟨<strong>a' b</strong>⟩ + > > ⟨<strong>a' b'</strong>⟩ - ⟨<strong>ab'</strong>⟩| ≤ 2 > > </p> > > > > <p>where <strong>a</strong>, <strong>a'</strong>, <strong>b</strong>, > > <strong>b'</strong> = 11</p> > > > > <p>is violated by quantum theory</p> > > > > <p></p> > > > > <h2>4.1.6 Maximal violation</h2> > > > > <p></p> > > > > <p><span style="text-decoration: underline">Cirelson's inequality</span>:</p> > > > > <p>||<strong>C</strong>|| ≤ 2√2</p> > > > > <p>where</p> > > > > <p><strong>C</strong> = <strong>ab</strong> + <strong>a' b</strong> + > > <strong>a' b'</strong> - <strong>a b'</strong></p> > > > > <p></p> > > > > <p></p> > > > > <p></p> > > > > <p></p> > > > > <p></p> > > </body> > > </html> > >
Received on Thursday, 14 June 2001 11:10:39 UTC