[Rd] Unclosed parenthesis in grep.Rd

[Martin Maechler]

>>>>> Hugh Parsonage <hugh.parsonage at gmail.com>
>>>>>     on Mon, 5 Mar 2018 13:39:24 +1100 writes:

    > Lines 129-131: \code{grep(value = FALSE)} returns a vector
    > of the indices of the elements of \code{x} that yielded a
    > match (or not, for \code{invert = TRUE}. This will be an
    > integer vector unless the input

    > There should be a closing parenthesis after \code{invert =
    > TRUE}

Thank you, Hugh!  I've added the ')' now.
Martin