Database
BASIC CATEGORY THEORY
Examples of categories
The category of extensible structures
estrreslem1
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estrreslem2
Metamath Proof Explorer
Ascii
Unicode
Theorem
estrreslem1
Description:
Lemma 1 for
estrres
.
(Contributed by
AV
, 14-Mar-2020)
Ref
Expression
Hypotheses
estrres.c
⊢
φ
→
C
=
Base
ndx
B
Hom
⁡
ndx
H
comp
⁡
ndx
·
˙
estrres.b
⊢
φ
→
B
∈
V
Assertion
estrreslem1
⊢
φ
→
B
=
Base
C
Proof
Step
Hyp
Ref
Expression
1
estrres.c
⊢
φ
→
C
=
Base
ndx
B
Hom
⁡
ndx
H
comp
⁡
ndx
·
˙
2
estrres.b
⊢
φ
→
B
∈
V
3
1
fveq2d
⊢
φ
→
Base
C
=
Base
Base
ndx
B
Hom
⁡
ndx
H
comp
⁡
ndx
·
˙
4
tpex
⊢
Base
ndx
B
Hom
⁡
ndx
H
comp
⁡
ndx
·
˙
∈
V
5
4
a1i
⊢
φ
→
Base
ndx
B
Hom
⁡
ndx
H
comp
⁡
ndx
·
˙
∈
V
6
df-base
⊢
Base
=
Slot
1
7
1nn
⊢
1
∈
ℕ
8
5
6
7
strndxid
⊢
φ
→
Base
ndx
B
Hom
⁡
ndx
H
comp
⁡
ndx
·
˙
⁡
Base
ndx
=
Base
Base
ndx
B
Hom
⁡
ndx
H
comp
⁡
ndx
·
˙
9
fvexd
⊢
φ
→
Base
ndx
∈
V
10
slotsbhcdif
⊢
Base
ndx
≠
Hom
⁡
ndx
∧
Base
ndx
≠
comp
⁡
ndx
∧
Hom
⁡
ndx
≠
comp
⁡
ndx
11
3simpa
⊢
Base
ndx
≠
Hom
⁡
ndx
∧
Base
ndx
≠
comp
⁡
ndx
∧
Hom
⁡
ndx
≠
comp
⁡
ndx
→
Base
ndx
≠
Hom
⁡
ndx
∧
Base
ndx
≠
comp
⁡
ndx
12
10
11
mp1i
⊢
φ
→
Base
ndx
≠
Hom
⁡
ndx
∧
Base
ndx
≠
comp
⁡
ndx
13
fvtp1g
⊢
Base
ndx
∈
V
∧
B
∈
V
∧
Base
ndx
≠
Hom
⁡
ndx
∧
Base
ndx
≠
comp
⁡
ndx
→
Base
ndx
B
Hom
⁡
ndx
H
comp
⁡
ndx
·
˙
⁡
Base
ndx
=
B
14
9
2
12
13
syl21anc
⊢
φ
→
Base
ndx
B
Hom
⁡
ndx
H
comp
⁡
ndx
·
˙
⁡
Base
ndx
=
B
15
3
8
14
3eqtr2rd
⊢
φ
→
B
=
Base
C