Database
BASIC TOPOLOGY
Metric spaces
The fundamental group
pco0
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pco1
Metamath Proof Explorer
Ascii
Unicode
Theorem
pco0
Description:
The starting point of a path concatenation.
(Contributed by
Jeff Madsen
, 15-Jun-2010)
Ref
Expression
Hypotheses
pcoval.2
⊢
φ
→
F
∈
II
Cn
J
pcoval.3
⊢
φ
→
G
∈
II
Cn
J
Assertion
pco0
⊢
φ
→
F
*
𝑝
⁡
J
G
⁡
0
=
F
⁡
0
Proof
Step
Hyp
Ref
Expression
1
pcoval.2
⊢
φ
→
F
∈
II
Cn
J
2
pcoval.3
⊢
φ
→
G
∈
II
Cn
J
3
0re
⊢
0
∈
ℝ
4
0le0
⊢
0
≤
0
5
halfge0
⊢
0
≤
1
2
6
halfre
⊢
1
2
∈
ℝ
7
3
6
elicc2i
⊢
0
∈
0
1
2
↔
0
∈
ℝ
∧
0
≤
0
∧
0
≤
1
2
8
3
4
5
7
mpbir3an
⊢
0
∈
0
1
2
9
1
2
pcoval1
⊢
φ
∧
0
∈
0
1
2
→
F
*
𝑝
⁡
J
G
⁡
0
=
F
⁡
2
⋅
0
10
8
9
mpan2
⊢
φ
→
F
*
𝑝
⁡
J
G
⁡
0
=
F
⁡
2
⋅
0
11
2t0e0
⊢
2
⋅
0
=
0
12
11
fveq2i
⊢
F
⁡
2
⋅
0
=
F
⁡
0
13
10
12
eqtrdi
⊢
φ
→
F
*
𝑝
⁡
J
G
⁡
0
=
F
⁡
0