Database
ZF (ZERMELO-FRAENKEL) SET THEORY
ZF Set Theory - add the Axiom of Union
Equinumerosity
sdomdom
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sdomnen
Metamath Proof Explorer
Ascii
Structured
Theorem
sdomdom
Description:
Strict dominance implies dominance.
(Contributed by
NM
, 10-Jun-1998)
Ref
Expression
Assertion
sdomdom
⊢
(
𝐴
≺
𝐵
→
𝐴
≼
𝐵
)
Proof
Step
Hyp
Ref
Expression
1
brsdom
⊢
(
𝐴
≺
𝐵
↔ (
𝐴
≼
𝐵
∧ ¬
𝐴
≈
𝐵
) )
2
1
simplbi
⊢
(
𝐴
≺
𝐵
→
𝐴
≼
𝐵
)