ACL2-PC_colon__colon_UP.html -- ACL2 Version 6.3

### ACL2-PC::UP

(primitive) `` move to the parent (or some ancestor) of the current subterm

    Major Section:  PROOF-CHECKER-COMMANDS

    Examples:  if the conclusion is (= x (* (- y) z)) and the
               current subterm is y, then we have:
    up or (up 1) -- the current subterm becomes (- y)
    (up 2)       -- the current subterm becomes (* (- y) z)
    (up 3)       -- the current subterm becomes the entire conclusion
    (up 4)       -- no change; can't go up that many levels

    General Form:
    (up &optional n)

Move up `n` levels in the conclusion from the current subterm, where `n` is a positive integer. If `n` is not supplied or is `nil`, then move up 1 level, i.e., treat the instruction as `(up 1)`.

See also `dive`, `top`, `nx`, and `bk`.