expand equalities in the transfer relation in transfer_prover if the relation doesn't follow the functional structure

--- a/src/HOL/Tools/Lifting/lifting_setup.ML	Tue Aug 06 23:24:10 2013 +0200
+++ b/src/HOL/Tools/Lifting/lifting_setup.ML	Wed Aug 07 15:40:29 2013 +0200
@@ -115,7 +115,8 @@
       val pcr_cr_eq = 
         pcr_rel_def
         |> Drule.cterm_instantiate args_inst    
-        |> Conv.fconv_rule (Conv.arg_conv (Conv.arg1_conv (bottom_rewr_conv (Transfer.get_relator_eq lthy))))
+        |> Conv.fconv_rule (Conv.arg_conv (Conv.arg1_conv 
+          (Transfer.bottom_rewr_conv (Transfer.get_relator_eq lthy))))
   in
     case (term_of o Thm.rhs_of) pcr_cr_eq of
       Const (@{const_name "relcompp"}, _) $ Const ("HOL.eq", _) $ _ => 

--- a/src/HOL/Tools/Lifting/lifting_util.ML	Tue Aug 06 23:24:10 2013 +0200
+++ b/src/HOL/Tools/Lifting/lifting_util.ML	Wed Aug 07 15:40:29 2013 +0200
@@ -26,7 +26,6 @@
   val is_Type: typ -> bool
   val is_fun_rel: term -> bool
   val relation_types: typ -> typ * typ
-  val bottom_rewr_conv: thm list -> conv
   val mk_HOL_eq: thm -> thm
   val safe_HOL_meta_eq: thm -> thm
 end;
@@ -107,8 +106,6 @@
     ([typ1, typ2], @{typ bool}) => (typ1, typ2)
     | _ => error "relation_types: not a relation"
 
-fun bottom_rewr_conv rewrs = Conv.bottom_conv (K (Conv.try_conv (Conv.rewrs_conv rewrs))) @{context}
-
 fun mk_HOL_eq r = r RS @{thm meta_eq_to_obj_eq}
 
 fun safe_HOL_meta_eq r = mk_HOL_eq r handle Thm.THM _ => r

--- a/src/HOL/Tools/transfer.ML	Tue Aug 06 23:24:10 2013 +0200
+++ b/src/HOL/Tools/transfer.ML	Wed Aug 07 15:40:29 2013 +0200
@@ -7,6 +7,9 @@
 
 signature TRANSFER =
 sig
+  val bottom_rewr_conv: thm list -> conv
+  val top_rewr_conv: thm list -> conv
+
   val prep_conv: conv
   val get_transfer_raw: Proof.context -> thm list
   val get_relator_eq: Proof.context -> thm list
@@ -132,6 +135,12 @@
 
 (** Conversions **)
 
+fun bottom_rewr_conv rewrs = Conv.bottom_conv (K (Conv.try_conv (Conv.rewrs_conv rewrs))) @{context}
+fun top_rewr_conv rewrs = Conv.top_conv (K (Conv.try_conv (Conv.rewrs_conv rewrs))) @{context}
+
+fun transfer_rel_conv conv = 
+  Conv.concl_conv ~1 (HOLogic.Trueprop_conv (Conv.fun2_conv (Conv.arg_conv conv)))
+
 val Rel_rule = Thm.symmetric @{thm Rel_def}
 
 fun dest_funcT cT =
@@ -559,11 +568,13 @@
     val rule1 = transfer_rule_of_term ctxt false rhs
     val rules = get_transfer_raw ctxt
     val eq_rules = get_relator_eq_raw ctxt
+    val expand_eq_in_rel = transfer_rel_conv (top_rewr_conv [@{thm fun_rel_eq[symmetric,THEN eq_reflection]}])
   in
     EVERY
       [CONVERSION prep_conv i,
        rtac @{thm transfer_prover_start} i,
-       (rtac rule1 THEN_ALL_NEW
+       ((rtac rule1 ORELSE' (CONVERSION expand_eq_in_rel THEN' rtac rule1))
+        THEN_ALL_NEW
          (REPEAT_ALL_NEW (resolve_tac rules) THEN_ALL_NEW (DETERM o eq_tac eq_rules))) (i+1),
        rtac @{thm refl} i]
   end)