ACL2-PC_colon__colon_THEN.html -- ACL2 Version 6.3

### ACL2-PC::THEN

(macro) `` apply one instruction to current goal and another to new subgoals

    Major Section:  PROOF-CHECKER-COMMANDS

    Example:
    (then induct prove)

    General Form:
    (then first-instruction &optional completion must-succeed-flg)

Run `first-instruction`, and then run `completion` (another instruction) on each subgoal created by `first-instruction`. If `must-succeed-flg` is supplied and not `nil`, then halt at the first ``failure'' and remove the effects of the invocation of `completion` that ``failed''.

The default for completion is `reduce`.