src/ZF/Cardinal.thy
changeset 32960 69916a850301
parent 26056 6a0801279f4c
child 39159 0dec18004e75
equal deleted inserted replaced
32959:23a8c5ac35f8 32960:69916a850301
     1 (*  Title:      ZF/Cardinal.thy
     1 (*  Title:      ZF/Cardinal.thy
     2     ID:         $Id$
       
     3     Author:     Lawrence C Paulson, Cambridge University Computer Laboratory
     2     Author:     Lawrence C Paulson, Cambridge University Computer Laboratory
     4     Copyright   1994  University of Cambridge
     3     Copyright   1994  University of Cambridge
     5 
       
     6 *)
     4 *)
     7 
     5 
     8 header{*Cardinal Numbers Without the Axiom of Choice*}
     6 header{*Cardinal Numbers Without the Axiom of Choice*}
     9 
     7 
    10 theory Cardinal imports OrderType Finite Nat_ZF Sum begin
     8 theory Cardinal imports OrderType Finite Nat_ZF Sum begin
    58 by (rule bnd_monoI, blast+)
    56 by (rule bnd_monoI, blast+)
    59 
    57 
    60 lemma Banach_last_equation:
    58 lemma Banach_last_equation:
    61     "g: Y->X
    59     "g: Y->X
    62      ==> g``(Y - f`` lfp(X, %W. X - g``(Y - f``W))) =        
    60      ==> g``(Y - f`` lfp(X, %W. X - g``(Y - f``W))) =        
    63 	 X - lfp(X, %W. X - g``(Y - f``W))" 
    61          X - lfp(X, %W. X - g``(Y - f``W))" 
    64 apply (rule_tac P = "%u. ?v = X-u" 
    62 apply (rule_tac P = "%u. ?v = X-u" 
    65        in decomp_bnd_mono [THEN lfp_unfold, THEN ssubst])
    63        in decomp_bnd_mono [THEN lfp_unfold, THEN ssubst])
    66 apply (simp add: double_complement  fun_is_rel [THEN image_subset])
    64 apply (simp add: double_complement  fun_is_rel [THEN image_subset])
    67 done
    65 done
    68 
    66