Database
BASIC TOPOLOGY
Metric spaces
Topology on the reals
iccconn
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Metamath Proof Explorer
Ascii
Unicode
Theorem
iccconn
Description:
A closed interval is connected.
(Contributed by
Jeff Hankins
, 17-Aug-2009)
Ref
Expression
Assertion
iccconn
⊢
A
∈
ℝ
∧
B
∈
ℝ
→
topGen
⁡
ran
⁡
.
↾
𝑡
A
B
∈
Conn
Proof
Step
Hyp
Ref
Expression
1
iccss2
⊢
x
∈
A
B
∧
y
∈
A
B
→
x
y
⊆
A
B
2
1
rgen2
⊢
∀
x
∈
A
B
∀
y
∈
A
B
x
y
⊆
A
B
3
iccssre
⊢
A
∈
ℝ
∧
B
∈
ℝ
→
A
B
⊆
ℝ
4
reconn
⊢
A
B
⊆
ℝ
→
topGen
⁡
ran
⁡
.
↾
𝑡
A
B
∈
Conn
↔
∀
x
∈
A
B
∀
y
∈
A
B
x
y
⊆
A
B
5
3
4
syl
⊢
A
∈
ℝ
∧
B
∈
ℝ
→
topGen
⁡
ran
⁡
.
↾
𝑡
A
B
∈
Conn
↔
∀
x
∈
A
B
∀
y
∈
A
B
x
y
⊆
A
B
6
2
5
mpbiri
⊢
A
∈
ℝ
∧
B
∈
ℝ
→
topGen
⁡
ran
⁡
.
↾
𝑡
A
B
∈
Conn