HomeHome Metamath Proof Explorer < Previous   Next >
Related theorems
Unicode version

Definition df-suc 2978
Description: Define the successor of a class. When applied to an ordinal number, the successor means the same thing as "plus 1" (see oa1suc 4295). Definition 7.22 of [TakeutiZaring] p. 41, who use "+ 1" to denote this function. Our definition is a generalization to classes. Although it is not conventional to use it with proper classes, it has no affect on a proper class (sucprc 3045), so that the successor of any ordinal class is still an ordinal class (ordsuc 3168), simplifying certain proofs. Some authors denote the successor operation with a prime (apostrophe-like) symbol, such as Definition 6 of [Suppes] p. 134 and the definition of successor in [Mendelson] p. 246 (who uses the symbol "Suc" as a predicate to mean "is a successor ordinal"). The definition of successor of [Enderton] p. 68 denotes the operation with a plus-sign superscript.
Assertion
Ref Expression
df-suc |- suc A = (A u. {A})

Detailed syntax breakdown of Definition df-suc
StepHypRef Expression
1 cA . . 3 class A
21csuc 2974 . 2 class suc A
31csn 2462 . . 3 class {A}
41, 3cun 2095 . 2 class (A u. {A})
52, 4wceq 989 1 wff suc A = (A u. {A})
Colors of variables: wff set class
This definition is referenced by:  suceq 3035  elsuci 3036  elsucg 3037  elsuc2g 3038  suc0 3044  sucprc 3045  unisuc 3046  sssucid 3047  sucid 3048  orddif 3062  sucexb 3163  suceloni 3167  onuninsuci 3191  tfrlem10 4216  df2o2 4272  oarec 4327  limensuci 4644  phplem1 4646  pssnn 4672  unifi 4692  fiint 4694  fodomfi 4700  pwfi 4705  pm54.43 4706  sucprcreg 4734  infensuc 4775  ranksuc 4837  unsnen 4974  sucxpdom 4987  cfsuc 5056  cda1en 5069
Copyright terms: Public domain