src/ZF/AC/WO6_WO1.ML
changeset 1461 6bcb44e4d6e5
parent 1450 19a256c8086d
child 2469 b50b8c0eec01
--- a/src/ZF/AC/WO6_WO1.ML	Mon Jan 29 14:16:13 1996 +0100
+++ b/src/ZF/AC/WO6_WO1.ML	Tue Jan 30 13:42:57 1996 +0100
@@ -1,6 +1,6 @@
-(*  Title: 	ZF/AC/WO6_WO1.ML
+(*  Title:      ZF/AC/WO6_WO1.ML
     ID:         $Id$
-    Author: 	Krzysztof Grabczewski
+    Author:     Krzysztof Grabczewski
 
 The proof of "WO6 ==> WO1".  Simplified by L C Paulson.
 
@@ -25,11 +25,11 @@
                                          (lt_oadd_odiff_disj RS disjE);
 
 (* ********************************************************************** *)
-(* The most complicated part of the proof - lemma ii - p. 2-4		  *)
+(* The most complicated part of the proof - lemma ii - p. 2-4             *)
 (* ********************************************************************** *)
 
 (* ********************************************************************** *)
-(* some properties of relation uu(beta, gamma, delta) - p. 2		  *)
+(* some properties of relation uu(beta, gamma, delta) - p. 2              *)
 (* ********************************************************************** *)
 
 goalw thy [uu_def] "domain(uu(f,b,g,d)) <= f`b";
@@ -39,7 +39,7 @@
 goal thy "!! a. ALL b<a. f`b lepoll m ==> \
 \               ALL b<a. ALL g<a. ALL d<a. domain(uu(f,b,g,d)) lepoll m";
 by (fast_tac (AC_cs addSEs
-	[domain_uu_subset RS subset_imp_lepoll RS lepoll_trans]) 1);
+        [domain_uu_subset RS subset_imp_lepoll RS lepoll_trans]) 1);
 val quant_domain_uu_lepoll_m = result();
 
 goalw thy [uu_def] "uu(f,b,g,d) <= f`b * f`g";
@@ -52,24 +52,24 @@
 
 goal thy "!! a. [| ALL b<a. f`b lepoll m;  d<a |] ==> uu(f,b,g,d) lepoll m";
 by (fast_tac (AC_cs
-	addSEs [uu_subset2 RS subset_imp_lepoll RS lepoll_trans]) 1);
+        addSEs [uu_subset2 RS subset_imp_lepoll RS lepoll_trans]) 1);
 val uu_lepoll_m = result();
 
 (* ********************************************************************** *)
-(* Two cases for lemma ii 						  *)
+(* Two cases for lemma ii                                                 *)
 (* ********************************************************************** *)
 goalw thy [lesspoll_def] 
   "!! a f u. ALL b<a. ALL g<a. ALL d<a. u(f,b,g,d) lepoll m ==>  \
 \            (ALL b<a. f`b ~= 0 --> (EX g<a. EX d<a. u(f,b,g,d) ~= 0 &  \
-\		           		u(f,b,g,d) lesspoll m)) |  \
+\                                       u(f,b,g,d) lesspoll m)) |  \
 \            (EX b<a. f`b ~= 0 & (ALL g<a. ALL d<a. u(f,b,g,d) ~= 0 -->  \
-\		           		u(f,b,g,d) eqpoll m))";
+\                                       u(f,b,g,d) eqpoll m))";
 by (asm_simp_tac OrdQuant_ss 1);
 by (fast_tac AC_cs 1);
 val cases = result();
 
 (* ********************************************************************** *)
-(* Lemmas used in both cases						  *)
+(* Lemmas used in both cases                                              *)
 (* ********************************************************************** *)
 goal thy "!!a C. Ord(a) ==> (UN b<a++a. C(b)) = (UN b<a. C(b) Un C(a++b))";
 by (fast_tac (AC_cs addSIs [equalityI] addIs [ltI] 
@@ -79,7 +79,7 @@
 
 
 (* ********************************************************************** *)
-(* Case 1 : lemmas							  *)
+(* Case 1 : lemmas                                                        *)
 (* ********************************************************************** *)
 
 goalw thy [vv1_def] "vv1(f,m,b) <= f`b";
@@ -89,16 +89,16 @@
 val vv1_subset = result();
 
 (* ********************************************************************** *)
-(* Case 1 : Union of images is the whole "y"				  *)
+(* Case 1 : Union of images is the whole "y"                              *)
 (* ********************************************************************** *)
 goalw thy [gg1_def]
-  "!! a f y. [| Ord(a);  m:nat |] ==>  	\
-\	     (UN b<a++a. gg1(f,a,m)`b) = (UN b<a. f`b)";
+  "!! a f y. [| Ord(a);  m:nat |] ==>   \
+\            (UN b<a++a. gg1(f,a,m)`b) = (UN b<a. f`b)";
 by (asm_simp_tac
     (OrdQuant_ss addsimps [UN_oadd, lt_oadd1,
-			   oadd_le_self RS le_imp_not_lt, lt_Ord,
-			   odiff_oadd_inverse, ltD,
-			   vv1_subset RS Diff_partition, ww1_def]) 1);
+                           oadd_le_self RS le_imp_not_lt, lt_Ord,
+                           odiff_oadd_inverse, ltD,
+                           vv1_subset RS Diff_partition, ww1_def]) 1);
 val UN_gg1_eq = result();
 
 goal thy "domain(gg1(f,a,m)) = a++a";
@@ -106,11 +106,11 @@
 val domain_gg1 = result();
 
 (* ********************************************************************** *)
-(* every value of defined function is less than or equipollent to m	  *)
+(* every value of defined function is less than or equipollent to m       *)
 (* ********************************************************************** *)
 goal thy "!!a b. [| P(a, b);  Ord(a);  Ord(b);  \
-\		Least_a = (LEAST a. EX x. Ord(x) & P(a, x)) |]  \
-\		==> P(Least_a, LEAST b. P(Least_a, b))";
+\               Least_a = (LEAST a. EX x. Ord(x) & P(a, x)) |]  \
+\               ==> P(Least_a, LEAST b. P(Least_a, b))";
 by (etac ssubst 1);
 by (res_inst_tac [("Q","%z. P(z, LEAST b. P(z, b))")] LeastI2 1);
 by (REPEAT (fast_tac (ZF_cs addSEs [LeastI]) 1));
@@ -119,24 +119,24 @@
 val nested_Least_instance = 
    standard
      (read_instantiate 
-	[("P","%g d. domain(uu(f,b,g,d)) ~= 0 &  \
-\		domain(uu(f,b,g,d)) lepoll m")] nested_LeastI);
+        [("P","%g d. domain(uu(f,b,g,d)) ~= 0 &  \
+\               domain(uu(f,b,g,d)) lepoll m")] nested_LeastI);
 
 goalw thy [gg1_def]
     "!!a. [| Ord(a);  m:nat;  \
-\	     ALL b<a. f`b ~=0 -->  					\
-\	     (EX g<a. EX d<a. domain(uu(f,b,g,d)) ~= 0  &  		\
-\	                      domain(uu(f,b,g,d)) lepoll m);    	\
-\            ALL b<a. f`b lepoll succ(m);  b<a++a			\
-\	  |] ==> gg1(f,a,m)`b lepoll m";
+\            ALL b<a. f`b ~=0 -->                                       \
+\            (EX g<a. EX d<a. domain(uu(f,b,g,d)) ~= 0  &               \
+\                             domain(uu(f,b,g,d)) lepoll m);            \
+\            ALL b<a. f`b lepoll succ(m);  b<a++a                       \
+\         |] ==> gg1(f,a,m)`b lepoll m";
 by (asm_simp_tac OrdQuant_ss 1);
 by (safe_tac (OrdQuant_cs addSEs [lt_oadd_odiff_cases]));
 (*Case b<a   : show vv1(f,m,b) lepoll m *)
 by (asm_simp_tac (ZF_ss addsimps [vv1_def, Let_def] 
                         setloop split_tac [expand_if]) 1);
 by (fast_tac (AC_cs addIs [nested_Least_instance RS conjunct2]
-		addSEs [lt_Ord]
-		addSIs [empty_lepollI]) 1);
+                addSEs [lt_Ord]
+                addSIs [empty_lepollI]) 1);
 (*Case a le b: show ww1(f,m,b--a) lepoll m *)
 by (asm_simp_tac (ZF_ss addsimps [ww1_def]) 1);
 by (excluded_middle_tac "f`(b--a) = 0" 1);
@@ -147,45 +147,45 @@
 by (dtac (ospec RS mp) 1);
 by (REPEAT (eresolve_tac [asm_rl, oexE] 1));
 by (asm_simp_tac (ZF_ss
-	addsimps [vv1_def, Let_def, lt_Ord, 
-		  nested_Least_instance RS conjunct1]) 1);
+        addsimps [vv1_def, Let_def, lt_Ord, 
+                  nested_Least_instance RS conjunct1]) 1);
 val gg1_lepoll_m = result();
 
 (* ********************************************************************** *)
-(* Case 2 : lemmas							  *)
+(* Case 2 : lemmas                                                        *)
 (* ********************************************************************** *)
 
 (* ********************************************************************** *)
-(* Case 2 : vv2_subset							  *)
+(* Case 2 : vv2_subset                                                    *)
 (* ********************************************************************** *)
 
-goalw thy [uu_def] "!!f. [| b<a;  g<a;  f`b~=0;  f`g~=0;  	\
-\			    y*y <= y;  (UN b<a. f`b)=y  	\
-\			 |] ==> EX d<a. uu(f,b,g,d) ~= 0";
+goalw thy [uu_def] "!!f. [| b<a;  g<a;  f`b~=0;  f`g~=0;        \
+\                           y*y <= y;  (UN b<a. f`b)=y          \
+\                        |] ==> EX d<a. uu(f,b,g,d) ~= 0";
 by (fast_tac (AC_cs addSIs [not_emptyI] 
-	  	    addSDs [SigmaI RSN (2, subsetD)]
-		    addSEs [not_emptyE]) 1);
+                    addSDs [SigmaI RSN (2, subsetD)]
+                    addSEs [not_emptyE]) 1);
 val ex_d_uu_not_empty = result();
 
 goal thy "!!f. [| b<a; g<a; f`b~=0; f`g~=0;  \
-\			y*y<=y;	(UN b<a. f`b)=y |]  \
-\		==> uu(f,b,g,LEAST d. (uu(f,b,g,d) ~= 0)) ~= 0";
+\                       y*y<=y; (UN b<a. f`b)=y |]  \
+\               ==> uu(f,b,g,LEAST d. (uu(f,b,g,d) ~= 0)) ~= 0";
 by (dtac ex_d_uu_not_empty 1 THEN REPEAT (assume_tac 1));
 by (fast_tac (AC_cs addSEs [LeastI, lt_Ord]) 1);
 val uu_not_empty = result();
 
 goal ZF.thy "!!r. [| r<=A*B; r~=0 |] ==> domain(r)~=0";
 by (REPEAT (eresolve_tac [asm_rl, not_emptyE, subsetD RS SigmaE, 
-		sym RSN (2, subst_elem) RS domainI RS not_emptyI] 1));
+                sym RSN (2, subst_elem) RS domainI RS not_emptyI] 1));
 val not_empty_rel_imp_domain = result();
 
 goal thy "!!f. [| b<a; g<a; f`b~=0; f`g~=0;  \
-\			y*y <= y; (UN b<a. f`b)=y |]  \
-\		==> (LEAST d. uu(f,b,g,d) ~= 0) < a";
+\                       y*y <= y; (UN b<a. f`b)=y |]  \
+\               ==> (LEAST d. uu(f,b,g,d) ~= 0) < a";
 by (eresolve_tac [ex_d_uu_not_empty RS oexE] 1
-	THEN REPEAT (assume_tac 1));
+        THEN REPEAT (assume_tac 1));
 by (resolve_tac [Least_le RS lt_trans1] 1
-	THEN (REPEAT (ares_tac [lt_Ord] 1)));
+        THEN (REPEAT (ares_tac [lt_Ord] 1)));
 val Least_uu_not_empty_lt_a = result();
 
 goal ZF.thy "!!B. [| B<=A; a~:B |] ==> B <= A-{a}";
@@ -202,56 +202,56 @@
 by (rtac subsetI 1);
 by (excluded_middle_tac "?P" 1 THEN (assume_tac 2));
 by (eresolve_tac [subset_Diff_sing RS subset_imp_lepoll RSN (2, 
-		Diff_sing_lepoll RSN (3, lepoll_trans RS lepoll_trans)) RS 
-		succ_lepoll_natE] 1
-	THEN REPEAT (assume_tac 1));
+                Diff_sing_lepoll RSN (3, lepoll_trans RS lepoll_trans)) RS 
+                succ_lepoll_natE] 1
+        THEN REPEAT (assume_tac 1));
 val supset_lepoll_imp_eq = result();
 
 goal thy
- "!!a. [| ALL g<a. ALL d<a. domain(uu(f, b, g, d))~=0 -->  		\
-\	  domain(uu(f, b, g, d)) eqpoll succ(m);  			\
-\	  ALL b<a. f`b lepoll succ(m);  y*y <= y;  			\
-\	  (UN b<a. f`b)=y;  b<a;  g<a;  d<a;  				\
-\	  f`b~=0;  f`g~=0;  m:nat;  s:f`b  				\
+ "!!a. [| ALL g<a. ALL d<a. domain(uu(f, b, g, d))~=0 -->               \
+\         domain(uu(f, b, g, d)) eqpoll succ(m);                        \
+\         ALL b<a. f`b lepoll succ(m);  y*y <= y;                       \
+\         (UN b<a. f`b)=y;  b<a;  g<a;  d<a;                            \
+\         f`b~=0;  f`g~=0;  m:nat;  s:f`b                               \
 \      |] ==> uu(f, b, g, LEAST d. uu(f,b,g,d)~=0) : f`b -> f`g";
 by (dres_inst_tac [("x2","g")] (ospec RS ospec RS mp) 1);
 by (rtac ([uu_subset1, uu_not_empty] MRS not_empty_rel_imp_domain) 3);
 by (rtac Least_uu_not_empty_lt_a 2 THEN TRYALL assume_tac);
 by (resolve_tac [eqpoll_sym RS eqpoll_imp_lepoll RS 
-	(Least_uu_not_empty_lt_a RSN (2, uu_lepoll_m) RSN (2, 
-	uu_subset1 RSN (4, rel_is_fun)))] 1
-	THEN TRYALL assume_tac);
+        (Least_uu_not_empty_lt_a RSN (2, uu_lepoll_m) RSN (2, 
+        uu_subset1 RSN (4, rel_is_fun)))] 1
+        THEN TRYALL assume_tac);
 by (rtac (eqpoll_sym RS eqpoll_imp_lepoll RSN (2, supset_lepoll_imp_eq)) 1);
 by (REPEAT (fast_tac (AC_cs addSIs [domain_uu_subset, nat_succI]) 1));
 val uu_Least_is_fun = result();
 
 goalw thy [vv2_def]
-    "!!a. [| ALL g<a. ALL d<a. domain(uu(f, b, g, d))~=0 -->		\
-\	     domain(uu(f, b, g, d)) eqpoll succ(m);			\
-\	     ALL b<a. f`b lepoll succ(m); y*y <= y;			\
-\	     (UN b<a. f`b)=y;  b<a;  g<a;  m:nat;  s:f`b		\
-\	   |] ==> vv2(f,b,g,s) <= f`g";
+    "!!a. [| ALL g<a. ALL d<a. domain(uu(f, b, g, d))~=0 -->            \
+\            domain(uu(f, b, g, d)) eqpoll succ(m);                     \
+\            ALL b<a. f`b lepoll succ(m); y*y <= y;                     \
+\            (UN b<a. f`b)=y;  b<a;  g<a;  m:nat;  s:f`b                \
+\          |] ==> vv2(f,b,g,s) <= f`g";
 by (split_tac [expand_if] 1);
 by (fast_tac (FOL_cs addSEs [uu_Least_is_fun]
-	             addSIs [empty_subsetI, not_emptyI, 
-			     singleton_subsetI, apply_type]) 1);
+                     addSIs [empty_subsetI, not_emptyI, 
+                             singleton_subsetI, apply_type]) 1);
 val vv2_subset = result();
 
 (* ********************************************************************** *)
-(* Case 2 : Union of images is the whole "y"				  *)
+(* Case 2 : Union of images is the whole "y"                              *)
 (* ********************************************************************** *)
 goalw thy [gg2_def]
-    "!!a. [| ALL g<a. ALL d<a. domain(uu(f,b,g,d)) ~= 0 -->  		\
-\	     domain(uu(f,b,g,d)) eqpoll succ(m);  			\
-\	     ALL b<a. f`b lepoll succ(m); y*y<=y;  			\
-\	     (UN b<a.f`b)=y;  Ord(a);  m:nat;  s:f`b;  b<a		\
-\	  |] ==> (UN g<a++a. gg2(f,a,b,s) ` g) = y";
+    "!!a. [| ALL g<a. ALL d<a. domain(uu(f,b,g,d)) ~= 0 -->             \
+\            domain(uu(f,b,g,d)) eqpoll succ(m);                        \
+\            ALL b<a. f`b lepoll succ(m); y*y<=y;                       \
+\            (UN b<a.f`b)=y;  Ord(a);  m:nat;  s:f`b;  b<a              \
+\         |] ==> (UN g<a++a. gg2(f,a,b,s) ` g) = y";
 by (dtac sym 1);
 by (asm_simp_tac
     (OrdQuant_ss addsimps [UN_oadd, lt_oadd1,
-			   oadd_le_self RS le_imp_not_lt, lt_Ord,
-			   odiff_oadd_inverse, ww2_def,
-			   vv2_subset RS Diff_partition]) 1);
+                           oadd_le_self RS le_imp_not_lt, lt_Ord,
+                           odiff_oadd_inverse, ww2_def,
+                           vv2_subset RS Diff_partition]) 1);
 val UN_gg2_eq = result();
 
 goal thy "domain(gg2(f,a,b,s)) = a++a";
@@ -259,7 +259,7 @@
 val domain_gg2 = result();
 
 (* ********************************************************************** *)
-(* every value of defined function is less than or equipollent to m	  *)
+(* every value of defined function is less than or equipollent to m       *)
 (* ********************************************************************** *)
 
 goalw thy [vv2_def]
@@ -267,28 +267,28 @@
 by (asm_simp_tac (OrdQuant_ss addsimps [empty_lepollI]
                               setloop split_tac [expand_if]) 1);
 by (fast_tac (AC_cs
-	addSDs [le_imp_subset RS subset_imp_lepoll RS lepoll_0_is_0]
-	addSIs [singleton_eqpoll_1 RS eqpoll_imp_lepoll RS lepoll_trans,
-		not_lt_imp_le RS le_imp_subset RS subset_imp_lepoll,
-		nat_into_Ord, nat_1I]) 1);
+        addSDs [le_imp_subset RS subset_imp_lepoll RS lepoll_0_is_0]
+        addSIs [singleton_eqpoll_1 RS eqpoll_imp_lepoll RS lepoll_trans,
+                not_lt_imp_le RS le_imp_subset RS subset_imp_lepoll,
+                nat_into_Ord, nat_1I]) 1);
 val vv2_lepoll = result();
 
 goalw thy [ww2_def]
     "!!m. [| ALL b<a. f`b lepoll succ(m);  g<a;  m:nat;  vv2(f,b,g,d) <= f`g  \
-\	  |] ==> ww2(f,b,g,d) lepoll m";
+\         |] ==> ww2(f,b,g,d) lepoll m";
 by (excluded_middle_tac "f`g = 0" 1);
 by (asm_simp_tac (OrdQuant_ss addsimps [empty_lepollI]) 2);
 by (dtac ospec 1 THEN (assume_tac 1));
 by (rtac Diff_lepoll 1
-	THEN (TRYALL assume_tac));
+        THEN (TRYALL assume_tac));
 by (asm_simp_tac (OrdQuant_ss addsimps [vv2_def, expand_if, not_emptyI]) 1);
 val ww2_lepoll = result();
 
 goalw thy [gg2_def]
-    "!!a. [| ALL g<a. ALL d<a. domain(uu(f,b,g,d)) ~= 0 -->		\
-\	     domain(uu(f,b,g,d)) eqpoll succ(m);			\
-\	     ALL b<a. f`b lepoll succ(m);  y*y <= y;			\
-\	     (UN b<a. f`b)=y;  b<a;  s:f`b;  m:nat;  m~= 0;  g<a++a	\
+    "!!a. [| ALL g<a. ALL d<a. domain(uu(f,b,g,d)) ~= 0 -->             \
+\            domain(uu(f,b,g,d)) eqpoll succ(m);                        \
+\            ALL b<a. f`b lepoll succ(m);  y*y <= y;                    \
+\            (UN b<a. f`b)=y;  b<a;  s:f`b;  m:nat;  m~= 0;  g<a++a     \
 \         |] ==> gg2(f,a,b,s) ` g lepoll m";
 by (asm_simp_tac OrdQuant_ss 1);
 by (safe_tac (OrdQuant_cs addSEs [lt_oadd_odiff_cases, lt_Ord2]));
@@ -297,10 +297,10 @@
 val gg2_lepoll_m = result();
 
 (* ********************************************************************** *)
-(* lemma ii	 							  *)
+(* lemma ii                                                               *)
 (* ********************************************************************** *)
 goalw thy [NN_def]
-	"!!y. [| succ(m) : NN(y); y*y <= y; m:nat; m~=0 |] ==> m : NN(y)";
+        "!!y. [| succ(m) : NN(y); y*y <= y; m:nat; m~=0 |] ==> m : NN(y)";
 by (REPEAT (eresolve_tac [CollectE, exE, conjE] 1));
 by (resolve_tac [quant_domain_uu_lepoll_m RS cases RS disjE] 1
     THEN (assume_tac 1));
@@ -308,7 +308,7 @@
 by (asm_full_simp_tac (ZF_ss addsimps [lesspoll_succ_iff]) 1);
 by (res_inst_tac [("x","a++a")] exI 1);
 by (fast_tac (OrdQuant_cs addSIs [Ord_oadd, domain_gg1, UN_gg1_eq, 
-				  gg1_lepoll_m]) 1);
+                                  gg1_lepoll_m]) 1);
 (* case 2 *)
 by (REPEAT (eresolve_tac [oexE, conjE] 1));
 by (res_inst_tac [("A","f`?B")] not_emptyE 1 THEN (assume_tac 1));
@@ -319,7 +319,7 @@
 (*Calling fast_tac might get rid of the res_inst_tac calls, but it
   is just too slow.*)
 by (asm_simp_tac (OrdQuant_ss addsimps 
-		  [Ord_oadd, domain_gg2, UN_gg2_eq, gg2_lepoll_m]) 1);
+                  [Ord_oadd, domain_gg2, UN_gg2_eq, gg2_lepoll_m]) 1);
 val lemma_ii = result();
 
 
@@ -344,7 +344,7 @@
 val le_subsets = result();
 
 goal thy "!!n m. [| n le m; m:nat |] ==>  \
-\	rec(n, x, %k r. r Un r*r) <= rec(m, x, %k r. r Un r*r)";
+\       rec(n, x, %k r. r Un r*r) <= rec(m, x, %k r. r Un r*r)";
 by (resolve_tac [z_n_subset_z_succ_n RS le_subsets] 1 
     THEN (TRYALL assume_tac));
 by (eresolve_tac [Ord_nat RSN (2, ltI) RSN (2, lt_trans1) RS ltD] 1
@@ -358,23 +358,23 @@
 by (res_inst_tac [("a","succ(n Un na)")] UN_I 1);
 by (eresolve_tac [Un_nat_type RS nat_succI] 1 THEN (assume_tac 1));
 by (fast_tac (ZF_cs addIs [le_imp_rec_subset RS subsetD]
-		addSIs [Un_upper1_le, Un_upper2_le, Un_nat_type]
-		addSEs [nat_into_Ord] addss nat_ss) 1);
+                addSIs [Un_upper1_le, Un_upper2_le, Un_nat_type]
+                addSEs [nat_into_Ord] addss nat_ss) 1);
 val lemma_iv = result();
 
 (* ********************************************************************** *)
-(* Rubin & Rubin wrote :						  *)
+(* Rubin & Rubin wrote :                                                  *)
 (* "It follows from (ii) and mathematical induction that if y*y <= y then *)
-(* y can be well-ordered"						  *)
+(* y can be well-ordered"                                                 *)
 
-(* In fact we have to prove :						  *)
-(*	* WO6 ==> NN(y) ~= 0						  *)
-(*	* reverse induction which lets us infer that 1 : NN(y)		  *)
-(*	* 1 : NN(y) ==> y can be well-ordered				  *)
+(* In fact we have to prove :                                             *)
+(*      * WO6 ==> NN(y) ~= 0                                              *)
+(*      * reverse induction which lets us infer that 1 : NN(y)            *)
+(*      * 1 : NN(y) ==> y can be well-ordered                             *)
 (* ********************************************************************** *)
 
 (* ********************************************************************** *)
-(*	WO6 ==> NN(y) ~= 0						  *)
+(*      WO6 ==> NN(y) ~= 0                                                *)
 (* ********************************************************************** *)
 
 goalw thy [WO6_def, NN_def] "!!y. WO6 ==> NN(y) ~= 0";
@@ -382,16 +382,16 @@
 val WO6_imp_NN_not_empty = result();
 
 (* ********************************************************************** *)
-(*	1 : NN(y) ==> y can be well-ordered				  *)
+(*      1 : NN(y) ==> y can be well-ordered                               *)
 (* ********************************************************************** *)
 
 goal thy "!!f. [| (UN b<a. f`b)=y; x:y; ALL b<a. f`b lepoll 1; Ord(a) |]  \
-\		==> EX c<a. f`c = {x}";
+\               ==> EX c<a. f`c = {x}";
 by (fast_tac (AC_cs addSEs [lepoll_1_is_sing]) 1);
 val lemma1 = result();
 
 goal thy "!!f. [| (UN b<a. f`b)=y; x:y; ALL b<a. f`b lepoll 1; Ord(a) |]  \
-\		==> f` (LEAST i. f`i = {x}) = {x}";
+\               ==> f` (LEAST i. f`i = {x}) = {x}";
 by (dtac lemma1 1 THEN REPEAT (assume_tac 1));
 by (fast_tac (AC_cs addSEs [lt_Ord] addIs [LeastI]) 1);
 val lemma2 = result();
@@ -415,12 +415,12 @@
 val y_well_ord = result();
 
 (* ********************************************************************** *)
-(*	reverse induction which lets us infer that 1 : NN(y)		  *)
+(*      reverse induction which lets us infer that 1 : NN(y)              *)
 (* ********************************************************************** *)
 
 val [prem1, prem2] = goal thy
-	"[| n:nat; !!m. [| m:nat; m~=0; P(succ(m)) |] ==> P(m) |]  \
-\	==> n~=0 --> P(n) --> P(1)";
+        "[| n:nat; !!m. [| m:nat; m~=0; P(succ(m)) |] ==> P(m) |]  \
+\       ==> n~=0 --> P(n) --> P(1)";
 by (res_inst_tac [("n","n")] nat_induct 1);
 by (rtac prem1 1);
 by (fast_tac ZF_cs 1);
@@ -430,9 +430,9 @@
 val rev_induct_lemma = result();
 
 val prems = goal thy
-	"[| P(n); n:nat; n~=0;  \
-\	!!m. [| m:nat; m~=0; P(succ(m)) |] ==> P(m) |]  \
-\	==> P(1)";
+        "[| P(n); n:nat; n~=0;  \
+\       !!m. [| m:nat; m~=0; P(succ(m)) |] ==> P(m) |]  \
+\       ==> P(1)";
 by (resolve_tac [rev_induct_lemma RS impE] 1);
 by (etac impE 4 THEN (assume_tac 5));
 by (REPEAT (ares_tac prems 1));
@@ -448,7 +448,7 @@
 val lemma3 = result();
 
 (* ********************************************************************** *)
-(* Main theorem "WO6 ==> WO1"						  *)
+(* Main theorem "WO6 ==> WO1"                                             *)
 (* ********************************************************************** *)
 
 (* another helpful lemma *)