RESQ_REWR_CANON transforms a theorem into a form accepted by COND_REWR_TAC.
The input theorem should be headed by a series of restricted universal
quantifications in the following form
!x1::P1. ... !xn::Pn. u[xi] = v[xi])
Other variables occurring in u and v may be universally quantified.
The output theorem will have all ordinary universal quantifications
moved to the outer most level with possible renaming to prevent
variable capture, and have all restricted universal quantifications
converted to implications. The output theorem will be in the
form accepted by COND_REWR_TAC.