Database
BASIC TOPOLOGY
Topology
Homeomorphisms
t0hmph
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t1hmph
Metamath Proof Explorer
Ascii
Unicode
Theorem
t0hmph
Description:
T_0 is a topological property.
(Contributed by
Mario Carneiro
, 25-Aug-2015)
Ref
Expression
Assertion
t0hmph
⊢
J
≃
K
→
J
∈
Kol2
→
K
∈
Kol2
Proof
Step
Hyp
Ref
Expression
1
t0top
⊢
J
∈
Kol2
→
J
∈
Top
2
cnt0
⊢
J
∈
Kol2
∧
f
:
⋃
K
⟶
1-1
⋃
J
∧
f
∈
K
Cn
J
→
K
∈
Kol2
3
1
2
haushmphlem
⊢
J
≃
K
→
J
∈
Kol2
→
K
∈
Kol2