[simplify].
'Command examples:   CHECK|: simplify.'.
'                    CHECK|: simplify h#1'.
'                    CHECK|: simplify c#1-2 & h#1-12'.
''.
'This command tidies up the current VC, rewriting terms such as'.
'(not (not X)) to X, (X and Y) to separate hypotheses/conclusions, etc.'.
''.
'(Note that any argument to "simplify" is ignored at present: the'.
'restructuring carried out by simplification is applied to the whole'.
'VC.  The command arguments will become supported in a future release'.
'of the Proof Checker.)'.
