Database
SUPPLEMENTARY MATERIAL (USERS' MATHBOXES)
Mathbox for Zhi Wang
Examples of categories
Parallel-arrow categories
parhomss2
Metamath Proof Explorer
Description: Variant of parhomss . (Contributed by Zhi Wang , 14-Sep-2026)
(Revised by Zhi Wang , 17-Sep-2026) (New usage is discouraged.)
(Proof modification is discouraged.)
Ref
Expression
Hypotheses
parhomval.h
⊢ H = x ∈ B , y ∈ B ⟼ if x = y J if x = X ∧ y = Y S ∅
parhomss.p
⊢ S ⊆ 𝒫 J
parhomss.f
⊢ φ → F ∈ U H V
parhomss2.s
⊢ S ∈ V
parhomss2.j
⊢ J ∈ V
parhomss2.u
⊢ φ → U ∈ B
parhomss2.v
⊢ φ → V ∈ B
Assertion
parhomss2
⊢ φ → F ⊆ J
Proof
Step
Hyp
Ref
Expression
1
parhomval.h
⊢ H = x ∈ B , y ∈ B ⟼ if x = y J if x = X ∧ y = Y S ∅
2
parhomss.p
⊢ S ⊆ 𝒫 J
3
parhomss.f
⊢ φ → F ∈ U H V
4
parhomss2.s
⊢ S ∈ V
5
parhomss2.j
⊢ J ∈ V
6
parhomss2.u
⊢ φ → U ∈ B
7
parhomss2.v
⊢ φ → V ∈ B
8
snsspw
⊢ J ⊆ 𝒫 J
9
2 8
unssi
⊢ S ∪ J ⊆ 𝒫 J
10
eqid
⊢ S ∪ J = S ∪ J
11
1 10 3
parhomcl
⊢ φ → F ∈ S ∪ J
12
9 11
sselid
⊢ φ → F ∈ 𝒫 J
13
12
elpwid
⊢ φ → F ⊆ J