src/ZF/Nat.thy
changeset 13628 87482b5e3f2e
parent 13524 604d0f3622d6
child 13784 b9f6154427a4
equal deleted inserted replaced
13627:67b0b7500a9d 13628:87482b5e3f2e
   107 lemma Limit_nat [iff]: "Limit(nat)"
   107 lemma Limit_nat [iff]: "Limit(nat)"
   108 apply (unfold Limit_def)
   108 apply (unfold Limit_def)
   109 apply (safe intro!: ltI Ord_nat)
   109 apply (safe intro!: ltI Ord_nat)
   110 apply (erule ltD)
   110 apply (erule ltD)
   111 done
   111 done
       
   112 
       
   113 lemma naturals_not_limit: "a \<in> nat ==> ~ Limit(a)"
       
   114 by (induct a rule: nat_induct, auto)
   112 
   115 
   113 lemma succ_natD [dest!]: "succ(i): nat ==> i: nat"
   116 lemma succ_natD [dest!]: "succ(i): nat ==> i: nat"
   114 by (rule Ord_trans [OF succI1], auto)
   117 by (rule Ord_trans [OF succI1], auto)
   115 
   118 
   116 lemma nat_succ_iff [iff]: "succ(n): nat <-> n: nat"
   119 lemma nat_succ_iff [iff]: "succ(n): nat <-> n: nat"