#' A description
#'
#' Long description
#' @param x the object of type \code{numeric}
#' @return A logical indicating whether \code{x == 0}
#' @export
is_zero = function (x) x == 0

#' Sum of numbers
#'
#' \code{sum_all} is a wrapper for \code{\link{sum}(..., na.rm = TRUE)}.
#' @param ... one or more numeric vectors
#' @examples
#' sum_all(1 : 10) # 55 @this \link{should not be highlighted!}
#' sum_all(1, NA, 2, 3) # 6
#' @seealso \link[base]{sum} # this SHOULD be highlighted again.
# comment
sum_all <- function (...) {
  sum(..., na.rm = TRUE)
}

# Weird identifier in @param string

#' @param `a\`b\\` test