Query or set tau system status
(tau-status :system t)
(tau-status :auto-mode nil)
(tau-status :system t :auto-mode nil)
(tau-status :system a :auto-mode b)
where a and b are Booleans. Both keyword arguments are optional
and they may be presented in either order. Value a controls whether the
tau-system is used during subsequent proofs. Value b controls
whether tau system rules are added automatically (``greedily'') when rules of
other rule-classes are added. If no arguments are supplied, this is
not an event and just returns an error-triple indicating the current
settings. See introduction-to-the-tau-system for background
The two flags are independent. For example, the tau system may be disabled
in proof attempts even though it is automatically (and silently) extending its
database as rules of other classes are added.
Flag (a) is actually toggled by enabling or disabling the :executable-counterpart of tau-system. Flag (b) is toggled with the
function set-tau-auto-mode, which manipulates the ACL2-defaults-table.
This macro expands into zero, one, or two events, as required by the
supplied values of flags a and b.
If no arguments are supplied the form is not an event and simply returns
(as an error-triple, (mv nil ans state)) the current settings of
the two flags. For example:
((:SYSTEM NIL) (:AUTO-MODE T))
intended to be self-explanatory.