Sorry, this one is cleaner and better:
Code:
alias hdec {
  var %0 = $($ $+ $0,2), %ifmatchbug = $ifmatch
  !hdec $1- $iif(%0 !isnum,1) $+ $iif(%ifmatchbug,$null)
}
A friend of mine just saw /hdec actually works if you supply a decrease value. Also, I don't get why did I think $show was needed here..

* cold edits his posts 24/7