Database
ZF (ZERMELO-FRAENKEL) SET THEORY
ZF Set Theory - add the Axiom of Power Sets
Founded and well-ordering relations
we0
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wereu
Metamath Proof Explorer
Ascii
Unicode
Theorem
we0
Description:
Any relation is a well-ordering of the empty set.
(Contributed by
NM
, 16-Mar-1997)
Ref
Expression
Assertion
we0
⊢
R
We
∅
Proof
Step
Hyp
Ref
Expression
1
fr0
⊢
R
Fr
∅
2
so0
⊢
R
Or
∅
3
df-we
⊢
R
We
∅
↔
R
Fr
∅
∧
R
Or
∅
4
1
2
3
mpbir2an
⊢
R
We
∅