IF YOU CAN SEE THIS go to http://www.cs.cornell.edu/Info/People/sfa/Nuprl/Shared/Xindentation_hack_doc.html
At:
himp antisym ax all
(t1:hbool. all
(t1:hbool. (t2:hbool. implies
(t1:hbool. (t2:hbool. (implies(t1,t2)
(t1:hbool. (t2:hbool. ,implies(implies(t2,t1),equal(t1,t2)))))