There is a typo in the grammar for list comprehensions in Section 3.11 of the Haskell report. It says, exp -> [ exp | qual_1, ..., qual_n ] (list comprehension, n >= 0) but I think, it should read `n >= 1'. At least, it says `n >= 1' five lines later and both GHC and Hugs raise an error when fed the expression `[1 |]'. Furthermore, I am unsure about the intention of the qual -> (empty qualifier) production, which would make `[1 | , ]' legal, or also `[1 | True, ]' - both of which GHC and Hugs don't like. I checked the errata, but didn't find a mention of these problems. (I didn't try nhc on these inputs.) Manuel
