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ZF (ZERMELO-FRAENKEL) SET THEORY
ZF Set Theory - add the Axiom of Union
Schroeder-Bernstein Theorem
sdomn2lp
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Metamath Proof Explorer
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Theorem
sdomn2lp
Description:
Strict dominance has no 2-cycle loops.
(Contributed by
NM
, 6-May-2008)
Ref
Expression
Assertion
sdomn2lp
⊢
¬
A
≺
B
∧
B
≺
A
Proof
Step
Hyp
Ref
Expression
1
sdomirr
⊢
¬
A
≺
A
2
sdomtr
⊢
A
≺
B
∧
B
≺
A
→
A
≺
A
3
1
2
mto
⊢
¬
A
≺
B
∧
B
≺
A