Major Section: PROOF-TREE
Also see proof-tree and see stop-proof-tree. Note that
:start-proof-tree works by removing
proof-tree from the
inhibit-output-lst; see set-inhibit-output-lst.
Explanations of proof tree displays may be found elsewhere: see proof-tree.
In a nutshell:
:start-proof-tree causes proof tree display to be turned
on, once it has been turned off by
Do not attempt to invoke
start-proof-tree during an interrupt in the
middle of a proof.