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1. • CommentRowNumber1.
   • CommentAuthorAndrew Stacey
   • CommentTimeNov 9th 2011
   • PermaLink
   Author: Andrew Stacey
   Format: MarkdownItexAdded [[parallelogram identity]] since it was linked from [[type (functional analysis)]]. Actually, I mostly stole the content from another wiki, ([this one](http://mathsnotes.math.ntnu.no/mathsnotes/show/from+angles+to+inner+products)) but I don't think that the original author will mind.

   Added parallelogram identity since it was linked from type (functional analysis). Actually, I mostly stole the content from another wiki, (this one) but I don’t think that the original author will mind.

2. • CommentRowNumber2.
   • CommentAuthorTim_Porter
   • CommentTimeNov 9th 2011
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   Author: Tim_Porter
   Format: MarkdownItexI would make sure by asking him! :-)

   I would make sure by asking him! :-)

3. • CommentRowNumber3.
   • CommentAuthorzskoda
   • CommentTimeNov 9th 2011
   • PermaLink
   Author: zskoda
   Format: MarkdownItexMaybe we should classify 2 into philosophy thread...on self-reflection...

   Maybe we should classify 2 into philosophy thread…on self-reflection…

4. • CommentRowNumber4.
   • CommentAuthorTodd_Trimble
   • CommentTimeNov 9th 2011
   • PermaLink
   Author: Todd_Trimble
   Format: MarkdownItexI added a little result to [[parallelogram identity]] that I've always liked, and which seems to fit the overall theme.

   I added a little result to parallelogram identity that I’ve always liked, and which seems to fit the overall theme.

5. • CommentRowNumber5.
   • CommentAuthorAndrew Stacey
   • CommentTimeNov 9th 2011
   • PermaLink
   Author: Andrew Stacey
   Format: MarkdownItexVery nice. Yes, I think that does fit the theme. Quite apart from where I stole the source from, I felt that either the page was going to be very short ("The parallelogram identity is ...") or it would have to take a slightly lower level approach. Being in a teach-y mood, I went for the latter. What might be nice to do is to list other characterisations of Hilbert spaces. I came across a few others when I asked about this on MO a long, long time ago.

   Very nice. Yes, I think that does fit the theme.

   Quite apart from where I stole the source from, I felt that either the page was going to be very short (“The parallelogram identity is …”) or it would have to take a slightly lower level approach. Being in a teach-y mood, I went for the latter.

   What might be nice to do is to list other characterisations of Hilbert spaces. I came across a few others when I asked about this on MO a long, long time ago.