I just pushed a very rough draft of the plain, informal text for pattern guards. I'm also attaching the patch. http://darcs.haskell.org/haskell-prime-report/report/exps.verb I'd like some feedback about the approach I'm taking, which varies slightly from the description in the 2000 HW paper. Since "pattern guards" are defined basically as in list comprehensions, I've pulled a bit of that text into its own section. In the list comprehensions section, pattern guards are referred to as "qualifiers", so I've kept that name. (From Simon's original memo, it seems that the generators within the qualifiers are pattern guards.) So now there's a section that explains qualifiers, including the nested environment nature. In many places, I've removed references to guards and replaced them with references to qualifiers. I've also consolidated text that explains guards, which was previously found in various locations, into that single section as above. I haven't touched the more semantic bits yet; I'd like some feedback on my overall approach first. I've brashly pushed these changes into our darcs repository of the report in the hopes that others on the committee (or indeed, within the community) will begin to be a bit more brash. Alas, I'm unable to actually build the report at the moment. If anyone knows how, please add instructions to the repository, or send them to me and I'll add them. peace, isaac p.s. the pattern guard wiki page is here: http://hackage.haskell.org/trac/haskell-prime/wiki/PatternGuards p.p.s. http://www.haskell.org/pipermail/cvs-ghc/2007-January/033592.html