(defrule first
    =>
    (assert (fire second)))

(defrule fire-second
    (fire second)
    =>
    (assert (fire third)))

(defrule fire-third
    (fire third)
    =>
    )

(set-break first)
(set-break fire-second)
(set-break fire-third)

(show-breaks)

(run)

(reset)
(remove-break first)
(show-breaks)
(run)