PURE_ONCE_REWRITE_CONV : (thm list -> conv)
Rewrites a term once with only the given list of rewrites.
PURE_ONCE_REWRITE_CONV generates rewrites from the list of theorems
supplied by the user, without including the tautologies given in
implicit_rewrites. The applicable rewrites are employeded once, without
entailing in a recursive search for matches over the term.
See GEN_REWRITE_CONV for more details about rewriting strategies in
This rule does not fail, and it does not diverge.