Database
ZF (ZERMELO-FRAENKEL) SET THEORY
ZF Set Theory - add the Axiom of Union
Ordinal arithmetic
df-2o
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df-3o
Metamath Proof Explorer
Ascii
Structured
Definition
df-2o
Description:
Define the ordinal number 2.
(Contributed by
NM
, 18-Feb-2004)
Ref
Expression
Assertion
df-2o
⊢
2
o
= suc 1
o
Detailed syntax breakdown
Step
Hyp
Ref
Expression
0
c2o
⊢
2
o
1
c1o
⊢
1
o
2
1
csuc
⊢
suc 1
o
3
0
2
wceq
⊢
2
o
= suc 1
o