Sets the backchain-limit used by the rewriter
Major Section:  EVENTS

Note: This is an event! It does not print the usual event summary but nevertheless changes the ACL2 logical world and is so recorded. Moreover, its effect is to set the acl2-defaults-table, and hence its effect is local to the book or encapsulate form containing it; see acl2-defaults-table.

This event sets the global backchain-limit used by the ACL2 rewriter. It must be nil or a non-negative integer. (See backchain-limit for details.)

:set-backchain-limit nil ; do not impose any additional limits
:set-backchain-limit 0   ; allow only type reasoning for relieving
                         ; hypotheses
:set-backchain-limit 500 ; allow backchaining to a depth of no more
                         ; than 500
The default limit is nil.