src/HOL/Library/normarith.ML

  let 
 (*   val _ = error "real_vector_ineq_prover: pause" *)
   val ntms = fold_rev find_normedterms (map (dest_arg o concl) (ges @ gts)) []
   val lctab = vector_lincombs (map snd (filter (not o fst) ntms))
   val (fxns, ctxt') = Variable.variant_fixes (replicate (length lctab) "x") ctxt
-  fun mk_norm t = capply (instantiate_cterm' [SOME (ctyp_of_term t)] [] @{cpat "norm :: (?'a :: norm) => real"}) t
+  fun mk_norm t = capply (instantiate_cterm' [SOME (ctyp_of_term t)] [] @{cpat "norm :: (?'a :: real_normed_vector) => real"}) t
   fun mk_equals l r = capply (capply (instantiate_cterm' [SOME (ctyp_of_term l)] [] @{cpat "op == :: ?'a =>_"}) l) r
   val asl = map2 (fn (t,_) => fn n => assume (mk_equals (mk_norm t) (cterm_of (ProofContext.theory_of ctxt') (Free(n,@{typ real}))))) lctab fxns
   val replace_conv = try_conv (rewrs_conv asl)
   val replace_rule = fconv_rule (funpow 2 arg_conv (replacenegnorms replace_conv))
   val ges' =