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ZF (ZERMELO-FRAENKEL) SET THEORY
ZF Set Theory - add the Axiom of Union
Equinumerosity
domentr
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Metamath Proof Explorer
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Theorem
domentr
Description:
Transitivity of dominance and equinumerosity.
(Contributed by
NM
, 7-Jun-1998)
Ref
Expression
Assertion
domentr
⊢
A
≼
B
∧
B
≈
C
→
A
≼
C
Proof
Step
Hyp
Ref
Expression
1
endom
⊢
B
≈
C
→
B
≼
C
2
domtr
⊢
A
≼
B
∧
B
≼
C
→
A
≼
C
3
1
2
sylan2
⊢
A
≼
B
∧
B
≈
C
→
A
≼
C