RESET-PREHISTORY.html -- ACL2 Version 6.3

## RESET-PREHISTORY

reset the prehistory

    Major Section:  SWITCHES-PARAMETERS-AND-MODES

    Examples:
    (reset-prehistory)     ; restart command numbering at 0
    (reset-prehistory nil) ; same as above
    (reset-prehistory t)   ; as above except also disable ubt-prehistory

    General Forms:
    (reset-prehistory)
    (reset-prehistory permanent-p)
    (reset-prehistory permanent-p doc-string)

where `permanent-p` is `t` or `nil`, and `doc-string` is an optional documentation string not beginning with ```:Doc-Section` ...''. After execution of this command, ACL2 will change the numbering provided by its history utilities so that this `reset-prehistory` command (or the top-level compound command containing it, which for example might be an `include-book`) is assigned the number 0. The only way to undo this command is with command `ubt-prehistory`. However, even that is disallowed if `permanent-p` is `t`.

Note that the second argument of `certify-book`, which specifies the number of commands in the certification world (i.e., since ground-zero), is not sensitive to `reset-prehistory`; rather, it expects the number of commands since ground-zero. To see such commands, `:``pbt``:start`.

A `reset-prehistory` event with value `nil` for `permanent-p` (the default) is always skipped during `certify-book` and `include-book` (indeed, whenever `ld-skip-proofsp` is `t`). Otherwise one would find the history numbering reset to 0 just by virtue of including (or certifying) a book -- probably not what was intended.

See ubt-prehistory for how to undo a `reset-prehistory` command that does not have a `permanent-p` of `t`.