--- a/src/ZF/Univ.ML Wed Dec 07 12:34:47 1994 +0100
+++ b/src/ZF/Univ.ML Wed Dec 07 13:12:04 1994 +0100
@@ -12,7 +12,7 @@
goal Univ.thy "Vfrom(A,i) = A Un (UN j:i. Pow(Vfrom(A,j)))";
by (rtac (Vfrom_def RS def_transrec RS ssubst) 1);
by (simp_tac ZF_ss 1);
-val Vfrom = result();
+qed "Vfrom";
(** Monotonicity **)
@@ -28,7 +28,7 @@
by (etac (bspec RS spec RS mp) 1);
by (assume_tac 1);
by (rtac subset_refl 1);
-val Vfrom_mono_lemma = result();
+qed "Vfrom_mono_lemma";
(* [| A<=B; i<=x |] ==> Vfrom(A,i) <= Vfrom(B,x) *)
val Vfrom_mono = standard (Vfrom_mono_lemma RS spec RS mp);
@@ -41,7 +41,7 @@
by (rtac (Vfrom RS ssubst) 1);
by (rtac (Vfrom RS ssubst) 1);
by (fast_tac (ZF_cs addSIs [rank_lt RS ltD]) 1);
-val Vfrom_rank_subset1 = result();
+qed "Vfrom_rank_subset1";
goal Univ.thy "Vfrom(A,rank(x)) <= Vfrom(A,x)";
by (eps_ind_tac "x" 1);
@@ -58,13 +58,13 @@
by (rtac (Ord_rank RS Ord_succ) 1);
by (etac bspec 1);
by (assume_tac 1);
-val Vfrom_rank_subset2 = result();
+qed "Vfrom_rank_subset2";
goal Univ.thy "Vfrom(A,rank(x)) = Vfrom(A,x)";
by (rtac equalityI 1);
by (rtac Vfrom_rank_subset2 1);
by (rtac Vfrom_rank_subset1 1);
-val Vfrom_rank_eq = result();
+qed "Vfrom_rank_eq";
(*** Basic closure properties ***)
@@ -72,58 +72,58 @@
goal Univ.thy "!!x y. y:x ==> 0 : Vfrom(A,x)";
by (rtac (Vfrom RS ssubst) 1);
by (fast_tac ZF_cs 1);
-val zero_in_Vfrom = result();
+qed "zero_in_Vfrom";
goal Univ.thy "i <= Vfrom(A,i)";
by (eps_ind_tac "i" 1);
by (rtac (Vfrom RS ssubst) 1);
by (fast_tac ZF_cs 1);
-val i_subset_Vfrom = result();
+qed "i_subset_Vfrom";
goal Univ.thy "A <= Vfrom(A,i)";
by (rtac (Vfrom RS ssubst) 1);
by (rtac Un_upper1 1);
-val A_subset_Vfrom = result();
+qed "A_subset_Vfrom";
val A_into_Vfrom = A_subset_Vfrom RS subsetD |> standard;
goal Univ.thy "!!A a i. a <= Vfrom(A,i) ==> a: Vfrom(A,succ(i))";
by (rtac (Vfrom RS ssubst) 1);
by (fast_tac ZF_cs 1);
-val subset_mem_Vfrom = result();
+qed "subset_mem_Vfrom";
(** Finite sets and ordered pairs **)
goal Univ.thy "!!a. a: Vfrom(A,i) ==> {a} : Vfrom(A,succ(i))";
by (rtac subset_mem_Vfrom 1);
by (safe_tac ZF_cs);
-val singleton_in_Vfrom = result();
+qed "singleton_in_Vfrom";
goal Univ.thy
"!!A. [| a: Vfrom(A,i); b: Vfrom(A,i) |] ==> {a,b} : Vfrom(A,succ(i))";
by (rtac subset_mem_Vfrom 1);
by (safe_tac ZF_cs);
-val doubleton_in_Vfrom = result();
+qed "doubleton_in_Vfrom";
goalw Univ.thy [Pair_def]
"!!A. [| a: Vfrom(A,i); b: Vfrom(A,i) |] ==> \
\ <a,b> : Vfrom(A,succ(succ(i)))";
by (REPEAT (ares_tac [doubleton_in_Vfrom] 1));
-val Pair_in_Vfrom = result();
+qed "Pair_in_Vfrom";
val [prem] = goal Univ.thy
"a<=Vfrom(A,i) ==> succ(a) : Vfrom(A,succ(succ(i)))";
by (REPEAT (resolve_tac [subset_mem_Vfrom, succ_subsetI] 1));
by (rtac (Vfrom_mono RSN (2,subset_trans)) 2);
by (REPEAT (resolve_tac [prem, subset_refl, subset_succI] 1));
-val succ_in_Vfrom = result();
+qed "succ_in_Vfrom";
(*** 0, successor and limit equations fof Vfrom ***)
goal Univ.thy "Vfrom(A,0) = A";
by (rtac (Vfrom RS ssubst) 1);
by (fast_tac eq_cs 1);
-val Vfrom_0 = result();
+qed "Vfrom_0";
goal Univ.thy "!!i. Ord(i) ==> Vfrom(A,succ(i)) = A Un Pow(Vfrom(A,i))";
by (rtac (Vfrom RS trans) 1);
@@ -133,14 +133,14 @@
by (rtac (subset_refl RS Vfrom_mono RS Pow_mono) 1);
by (etac (ltI RS le_imp_subset) 1);
by (etac Ord_succ 1);
-val Vfrom_succ_lemma = result();
+qed "Vfrom_succ_lemma";
goal Univ.thy "Vfrom(A,succ(i)) = A Un Pow(Vfrom(A,i))";
by (res_inst_tac [("x1", "succ(i)")] (Vfrom_rank_eq RS subst) 1);
by (res_inst_tac [("x1", "i")] (Vfrom_rank_eq RS subst) 1);
by (rtac (rank_succ RS ssubst) 1);
by (rtac (Ord_rank RS Vfrom_succ_lemma) 1);
-val Vfrom_succ = result();
+qed "Vfrom_succ";
(*The premise distinguishes this from Vfrom(A,0); allowing X=0 forces
the conclusion to be Vfrom(A,Union(X)) = A Un (UN y:X. Vfrom(A,y)) *)
@@ -161,11 +161,11 @@
by (rtac UN_least 1);
by (rtac (Vfrom RS ssubst) 1);
by (fast_tac ZF_cs 1);
-val Vfrom_Union = result();
+qed "Vfrom_Union";
goal Univ.thy "!!i. Ord(i) ==> i=0 | (EX j. i=succ(j)) | Limit(i)";
by (fast_tac (ZF_cs addSIs [non_succ_LimitI, Ord_0_lt]) 1);
-val Ord_cases_lemma = result();
+qed "Ord_cases_lemma";
val major::prems = goal Univ.thy
"[| Ord(i); \
@@ -175,7 +175,7 @@
\ |] ==> P";
by (cut_facts_tac [major RS Ord_cases_lemma] 1);
by (REPEAT (eresolve_tac (prems@[disjE, exE]) 1));
-val Ord_cases = result();
+qed "Ord_cases";
(*** Vfrom applied to Limit ordinals ***)
@@ -187,12 +187,12 @@
by (rtac (limiti RS (Limit_has_0 RS ltD) RS Vfrom_Union RS subst) 1);
by (rtac (limiti RS Limit_Union_eq RS ssubst) 1);
by (rtac refl 1);
-val Limit_Vfrom_eq = result();
+qed "Limit_Vfrom_eq";
goal Univ.thy "!!a. [| a: Vfrom(A,j); Limit(i); j<i |] ==> a : Vfrom(A,i)";
by (rtac (Limit_Vfrom_eq RS equalityD2 RS subsetD) 1);
by (REPEAT (ares_tac [ltD RS UN_I] 1));
-val Limit_VfromI = result();
+qed "Limit_VfromI";
val prems = goal Univ.thy
"[| a: Vfrom(A,i); Limit(i); \
@@ -200,7 +200,7 @@
\ |] ==> R";
by (rtac (Limit_Vfrom_eq RS equalityD1 RS subsetD RS UN_E) 1);
by (REPEAT (ares_tac (prems @ [ltI, Limit_is_Ord]) 1));
-val Limit_VfromE = result();
+qed "Limit_VfromE";
val zero_in_VLimit = Limit_has_0 RS ltD RS zero_in_Vfrom;
@@ -209,7 +209,7 @@
by (rtac ([major,limiti] MRS Limit_VfromE) 1);
by (etac ([singleton_in_Vfrom, limiti] MRS Limit_VfromI) 1);
by (etac (limiti RS Limit_has_succ) 1);
-val singleton_in_VLimit = result();
+qed "singleton_in_VLimit";
val Vfrom_UnI1 = Un_upper1 RS (subset_refl RS Vfrom_mono RS subsetD)
and Vfrom_UnI2 = Un_upper2 RS (subset_refl RS Vfrom_mono RS subsetD);
@@ -224,7 +224,7 @@
by (etac Vfrom_UnI1 1);
by (etac Vfrom_UnI2 1);
by (REPEAT (ares_tac [limiti, Limit_has_succ, Un_least_lt] 1));
-val doubleton_in_VLimit = result();
+qed "doubleton_in_VLimit";
val [aprem,bprem,limiti] = goal Univ.thy
"[| a: Vfrom(A,i); b: Vfrom(A,i); Limit(i) |] ==> \
@@ -237,12 +237,12 @@
by (etac Vfrom_UnI1 1);
by (etac Vfrom_UnI2 1);
by (REPEAT (ares_tac [limiti, Limit_has_succ, Un_least_lt] 1));
-val Pair_in_VLimit = result();
+qed "Pair_in_VLimit";
goal Univ.thy "!!i. Limit(i) ==> Vfrom(A,i)*Vfrom(A,i) <= Vfrom(A,i)";
by (REPEAT (ares_tac [subsetI,Pair_in_VLimit] 1
ORELSE eresolve_tac [SigmaE, ssubst] 1));
-val product_VLimit = result();
+qed "product_VLimit";
val Sigma_subset_VLimit =
[Sigma_mono, product_VLimit] MRS subset_trans |> standard;
@@ -253,7 +253,7 @@
goal Univ.thy "!!i. [| n: nat; Limit(i) |] ==> n : Vfrom(A,i)";
by (REPEAT (ares_tac [nat_subset_VLimit RS subsetD] 1));
-val nat_into_VLimit = result();
+qed "nat_into_VLimit";
(** Closure under disjoint union **)
@@ -261,21 +261,21 @@
goal Univ.thy "!!i. Limit(i) ==> 1 : Vfrom(A,i)";
by (REPEAT (ares_tac [nat_into_VLimit, nat_0I, nat_succI] 1));
-val one_in_VLimit = result();
+qed "one_in_VLimit";
goalw Univ.thy [Inl_def]
"!!A a. [| a: Vfrom(A,i); Limit(i) |] ==> Inl(a) : Vfrom(A,i)";
by (REPEAT (ares_tac [zero_in_VLimit, Pair_in_VLimit] 1));
-val Inl_in_VLimit = result();
+qed "Inl_in_VLimit";
goalw Univ.thy [Inr_def]
"!!A b. [| b: Vfrom(A,i); Limit(i) |] ==> Inr(b) : Vfrom(A,i)";
by (REPEAT (ares_tac [one_in_VLimit, Pair_in_VLimit] 1));
-val Inr_in_VLimit = result();
+qed "Inr_in_VLimit";
goal Univ.thy "!!i. Limit(i) ==> Vfrom(C,i)+Vfrom(C,i) <= Vfrom(C,i)";
by (fast_tac (sum_cs addSIs [Inl_in_VLimit, Inr_in_VLimit]) 1);
-val sum_VLimit = result();
+qed "sum_VLimit";
val sum_subset_VLimit =
[sum_mono, sum_VLimit] MRS subset_trans |> standard;
@@ -289,7 +289,7 @@
by (rtac (Vfrom RS ssubst) 1);
by (fast_tac (ZF_cs addSIs [Transset_Union_family, Transset_Un,
Transset_Pow]) 1);
-val Transset_Vfrom = result();
+qed "Transset_Vfrom";
goal Univ.thy "!!A i. Transset(A) ==> Vfrom(A, succ(i)) = Pow(Vfrom(A,i))";
by (rtac (Vfrom_succ RS trans) 1);
@@ -297,12 +297,12 @@
by (rtac (subset_refl RSN (2,Un_least)) 1);
by (rtac (A_subset_Vfrom RS subset_trans) 1);
by (etac (Transset_Vfrom RS (Transset_iff_Pow RS iffD1)) 1);
-val Transset_Vfrom_succ = result();
+qed "Transset_Vfrom_succ";
goalw Ordinal.thy [Pair_def,Transset_def]
"!!C. [| <a,b> <= C; Transset(C) |] ==> a: C & b: C";
by (fast_tac ZF_cs 1);
-val Transset_Pair_subset = result();
+qed "Transset_Pair_subset";
goal Univ.thy
"!!a b.[| <a,b> <= Vfrom(A,i); Transset(A); Limit(i) |] ==> \
@@ -310,7 +310,7 @@
by (etac (Transset_Pair_subset RS conjE) 1);
by (etac Transset_Vfrom 1);
by (REPEAT (ares_tac [Pair_in_VLimit] 1));
-val Transset_Pair_subset_VLimit = result();
+qed "Transset_Pair_subset_VLimit";
(*** Closure under product/sum applied to elements -- thus Vfrom(A,i)
@@ -333,7 +333,7 @@
by (etac (Vfrom_UnI1 RS Vfrom_UnI1) 3);
by (rtac (succI1 RS UnI2) 2);
by (REPEAT (ares_tac [limiti, Limit_has_0, Limit_has_succ, Un_least_lt] 1));
-val in_VLimit = result();
+qed "in_VLimit";
(** products **)
@@ -344,7 +344,7 @@
by (rtac subset_mem_Vfrom 1);
by (rewtac Transset_def);
by (fast_tac (ZF_cs addIs [Pair_in_Vfrom]) 1);
-val prod_in_Vfrom = result();
+qed "prod_in_Vfrom";
val [aprem,bprem,limiti,transset] = goal Univ.thy
"[| a: Vfrom(A,i); b: Vfrom(A,i); Limit(i); Transset(A) |] ==> \
@@ -352,7 +352,7 @@
by (rtac ([aprem,bprem,limiti] MRS in_VLimit) 1);
by (REPEAT (ares_tac [exI, conjI, prod_in_Vfrom, transset,
limiti RS Limit_has_succ] 1));
-val prod_in_VLimit = result();
+qed "prod_in_VLimit";
(** Disjoint sums, aka Quine ordered pairs **)
@@ -364,7 +364,7 @@
by (rewtac Transset_def);
by (fast_tac (ZF_cs addIs [zero_in_Vfrom, Pair_in_Vfrom,
i_subset_Vfrom RS subsetD]) 1);
-val sum_in_Vfrom = result();
+qed "sum_in_Vfrom";
val [aprem,bprem,limiti,transset] = goal Univ.thy
"[| a: Vfrom(A,i); b: Vfrom(A,i); Limit(i); Transset(A) |] ==> \
@@ -372,7 +372,7 @@
by (rtac ([aprem,bprem,limiti] MRS in_VLimit) 1);
by (REPEAT (ares_tac [exI, conjI, sum_in_Vfrom, transset,
limiti RS Limit_has_succ] 1));
-val sum_in_VLimit = result();
+qed "sum_in_VLimit";
(** function space! **)
@@ -389,7 +389,7 @@
by (rtac Pow_mono 1);
by (rewtac Transset_def);
by (fast_tac (ZF_cs addIs [Pair_in_Vfrom]) 1);
-val fun_in_Vfrom = result();
+qed "fun_in_Vfrom";
val [aprem,bprem,limiti,transset] = goal Univ.thy
"[| a: Vfrom(A,i); b: Vfrom(A,i); Limit(i); Transset(A) |] ==> \
@@ -397,7 +397,7 @@
by (rtac ([aprem,bprem,limiti] MRS in_VLimit) 1);
by (REPEAT (ares_tac [exI, conjI, fun_in_Vfrom, transset,
limiti RS Limit_has_succ] 1));
-val fun_in_VLimit = result();
+qed "fun_in_VLimit";
(*** The set Vset(i) ***)
@@ -405,7 +405,7 @@
goal Univ.thy "Vset(i) = (UN j:i. Pow(Vset(j)))";
by (rtac (Vfrom RS ssubst) 1);
by (fast_tac eq_cs 1);
-val Vset = result();
+qed "Vset";
val Vset_succ = Transset_0 RS Transset_Vfrom_succ;
@@ -421,7 +421,7 @@
by (rtac UN_succ_least_lt 1);
by (fast_tac ZF_cs 2);
by (REPEAT (ares_tac [ltI] 1));
-val Vset_rank_imp1 = result();
+qed "Vset_rank_imp1";
(* [| Ord(i); x : Vset(i) |] ==> rank(x) < i *)
val VsetD = standard (Vset_rank_imp1 RS spec RS mp);
@@ -431,23 +431,23 @@
by (rtac allI 1);
by (rtac (Vset RS ssubst) 1);
by (fast_tac (ZF_cs addSIs [rank_lt RS ltD]) 1);
-val Vset_rank_imp2 = result();
+qed "Vset_rank_imp2";
goal Univ.thy "!!x i. rank(x)<i ==> x : Vset(i)";
by (etac ltE 1);
by (etac (Vset_rank_imp2 RS spec RS mp) 1);
by (assume_tac 1);
-val VsetI = result();
+qed "VsetI";
goal Univ.thy "!!i. Ord(i) ==> b : Vset(i) <-> rank(b) < i";
by (rtac iffI 1);
by (REPEAT (eresolve_tac [asm_rl, VsetD, VsetI] 1));
-val Vset_Ord_rank_iff = result();
+qed "Vset_Ord_rank_iff";
goal Univ.thy "b : Vset(a) <-> rank(b) < rank(a)";
by (rtac (Vfrom_rank_eq RS subst) 1);
by (rtac (Ord_rank RS Vset_Ord_rank_iff) 1);
-val Vset_rank_iff = result();
+qed "Vset_rank_iff";
goal Univ.thy "!!i. Ord(i) ==> rank(Vset(i)) = i";
by (rtac (rank RS ssubst) 1);
@@ -459,21 +459,21 @@
assume_tac,
rtac succI1] 3);
by (REPEAT (eresolve_tac [asm_rl, VsetD RS ltD, Ord_trans] 1));
-val rank_Vset = result();
+qed "rank_Vset";
(** Lemmas for reasoning about sets in terms of their elements' ranks **)
goal Univ.thy "a <= Vset(rank(a))";
by (rtac subsetI 1);
by (etac (rank_lt RS VsetI) 1);
-val arg_subset_Vset_rank = result();
+qed "arg_subset_Vset_rank";
val [iprem] = goal Univ.thy
"[| !!i. Ord(i) ==> a Int Vset(i) <= b |] ==> a <= b";
by (rtac ([subset_refl, arg_subset_Vset_rank] MRS
Int_greatest RS subset_trans) 1);
by (rtac (Ord_rank RS iprem) 1);
-val Int_Vset_subset = result();
+qed "Int_Vset_subset";
(** Set up an environment for simplification **)
@@ -491,7 +491,7 @@
by (rtac (transrec RS ssubst) 1);
by (simp_tac (ZF_ss addsimps [Ord_rank, Ord_succ, VsetD RS ltD RS beta,
VsetI RS beta, le_refl]) 1);
-val Vrec = result();
+qed "Vrec";
(*This form avoids giant explosions in proofs. NOTE USE OF == *)
val rew::prems = goal Univ.thy
@@ -499,7 +499,7 @@
\ h(a) = H(a, lam x: Vset(rank(a)). h(x))";
by (rewtac rew);
by (rtac Vrec 1);
-val def_Vrec = result();
+qed "def_Vrec";
(*** univ(A) ***)
@@ -507,22 +507,22 @@
goalw Univ.thy [univ_def] "!!A B. A<=B ==> univ(A) <= univ(B)";
by (etac Vfrom_mono 1);
by (rtac subset_refl 1);
-val univ_mono = result();
+qed "univ_mono";
goalw Univ.thy [univ_def] "!!A. Transset(A) ==> Transset(univ(A))";
by (etac Transset_Vfrom 1);
-val Transset_univ = result();
+qed "Transset_univ";
(** univ(A) as a limit **)
goalw Univ.thy [univ_def] "univ(A) = (UN i:nat. Vfrom(A,i))";
by (rtac (Limit_nat RS Limit_Vfrom_eq) 1);
-val univ_eq_UN = result();
+qed "univ_eq_UN";
goal Univ.thy "!!c. c <= univ(A) ==> c = (UN i:nat. c Int Vfrom(A,i))";
by (rtac (subset_UN_iff_eq RS iffD1) 1);
by (etac (univ_eq_UN RS subst) 1);
-val subset_univ_eq_Int = result();
+qed "subset_univ_eq_Int";
val [aprem, iprem] = goal Univ.thy
"[| a <= univ(X); \
@@ -531,7 +531,7 @@
by (rtac (aprem RS subset_univ_eq_Int RS ssubst) 1);
by (rtac UN_least 1);
by (etac iprem 1);
-val univ_Int_Vfrom_subset = result();
+qed "univ_Int_Vfrom_subset";
val prems = goal Univ.thy
"[| a <= univ(X); b <= univ(X); \
@@ -542,17 +542,17 @@
(resolve_tac (prems RL [univ_Int_Vfrom_subset]) THEN'
eresolve_tac (prems RL [equalityD1,equalityD2] RL [subset_trans]) THEN'
rtac Int_lower1));
-val univ_Int_Vfrom_eq = result();
+qed "univ_Int_Vfrom_eq";
(** Closure properties **)
goalw Univ.thy [univ_def] "0 : univ(A)";
by (rtac (nat_0I RS zero_in_Vfrom) 1);
-val zero_in_univ = result();
+qed "zero_in_univ";
goalw Univ.thy [univ_def] "A <= univ(A)";
by (rtac A_subset_Vfrom 1);
-val A_subset_univ = result();
+qed "A_subset_univ";
val A_into_univ = A_subset_univ RS subsetD;
@@ -560,28 +560,28 @@
goalw Univ.thy [univ_def] "!!A a. a: univ(A) ==> {a} : univ(A)";
by (REPEAT (ares_tac [singleton_in_VLimit, Limit_nat] 1));
-val singleton_in_univ = result();
+qed "singleton_in_univ";
goalw Univ.thy [univ_def]
"!!A a. [| a: univ(A); b: univ(A) |] ==> {a,b} : univ(A)";
by (REPEAT (ares_tac [doubleton_in_VLimit, Limit_nat] 1));
-val doubleton_in_univ = result();
+qed "doubleton_in_univ";
goalw Univ.thy [univ_def]
"!!A a. [| a: univ(A); b: univ(A) |] ==> <a,b> : univ(A)";
by (REPEAT (ares_tac [Pair_in_VLimit, Limit_nat] 1));
-val Pair_in_univ = result();
+qed "Pair_in_univ";
goalw Univ.thy [univ_def] "univ(A)*univ(A) <= univ(A)";
by (rtac (Limit_nat RS product_VLimit) 1);
-val product_univ = result();
+qed "product_univ";
(** The natural numbers **)
goalw Univ.thy [univ_def] "nat <= univ(A)";
by (rtac i_subset_Vfrom 1);
-val nat_subset_univ = result();
+qed "nat_subset_univ";
(* n:nat ==> n:univ(A) *)
val nat_into_univ = standard (nat_subset_univ RS subsetD);
@@ -590,16 +590,16 @@
goalw Univ.thy [univ_def] "1 : univ(A)";
by (rtac (Limit_nat RS one_in_VLimit) 1);
-val one_in_univ = result();
+qed "one_in_univ";
(*unused!*)
goal Univ.thy "succ(1) : univ(A)";
by (REPEAT (ares_tac [nat_into_univ, nat_0I, nat_succI] 1));
-val two_in_univ = result();
+qed "two_in_univ";
goalw Univ.thy [bool_def] "bool <= univ(A)";
by (fast_tac (ZF_cs addSIs [zero_in_univ,one_in_univ]) 1);
-val bool_subset_univ = result();
+qed "bool_subset_univ";
val bool_into_univ = standard (bool_subset_univ RS subsetD);
@@ -608,15 +608,15 @@
goalw Univ.thy [univ_def] "!!A a. a: univ(A) ==> Inl(a) : univ(A)";
by (etac (Limit_nat RSN (2,Inl_in_VLimit)) 1);
-val Inl_in_univ = result();
+qed "Inl_in_univ";
goalw Univ.thy [univ_def] "!!A b. b: univ(A) ==> Inr(b) : univ(A)";
by (etac (Limit_nat RSN (2,Inr_in_VLimit)) 1);
-val Inr_in_univ = result();
+qed "Inr_in_univ";
goalw Univ.thy [univ_def] "univ(C)+univ(C) <= univ(C)";
by (rtac (Limit_nat RS sum_VLimit) 1);
-val sum_univ = result();
+qed "sum_univ";
val sum_subset_univ = [sum_mono, sum_univ] MRS subset_trans |> standard;