Metamath Proof Explorer


Theorem nelsubclem

Description: Lemma for nelsubc . (Contributed by Zhi Wang, 5-Nov-2025)

Ref Expression
Hypotheses nelsubc.b ⊢ B = Base C
nelsubc.s ⊢ φ → S ⊆ B
nelsubc.0 ⊢ φ → S ≠ ∅
nelsubc.j ⊢ φ → J = S × S × ∅
nelsubc.h ⊢ H = Hom 𝑓 ⁡ C
Assertion nelsubclem ⊢ φ → J Fn S × S ∧ J ⊆ cat H ∧ ¬ ∀ x ∈ S I ∈ x J x ∧ ∀ x ∈ S ∀ y ∈ S ∀ z ∈ S ∀ f ∈ x J y ψ

Proof

Step Hyp Ref Expression
1 nelsubc.b ⊢ B = Base C
2 nelsubc.s ⊢ φ → S ⊆ B
3 nelsubc.0 ⊢ φ → S ≠ ∅
4 nelsubc.j ⊢ φ → J = S × S × ∅
5 nelsubc.h ⊢ H = Hom 𝑓 ⁡ C
6 0ex ⊢ ∅ ∈ V
7 fnconstg ⊢ ∅ ∈ V → S × S × ∅ Fn S × S
8 6 7 ax-mp ⊢ S × S × ∅ Fn S × S
9 4 fneq1d ⊢ φ → J Fn S × S ↔ S × S × ∅ Fn S × S
10 8 9 mpbiri ⊢ φ → J Fn S × S
11 4 oveqd ⊢ φ → p J q = p S × S × ∅ q
12 6 ovconst2 ⊢ p ∈ S ∧ q ∈ S → p S × S × ∅ q = ∅
13 11 12 sylan9eq ⊢ φ ∧ p ∈ S ∧ q ∈ S → p J q = ∅
14 0ss ⊢ ∅ ⊆ p H q
15 13 14 eqsstrdi ⊢ φ ∧ p ∈ S ∧ q ∈ S → p J q ⊆ p H q
16 15 ralrimivva ⊢ φ → ∀ p ∈ S ∀ q ∈ S p J q ⊆ p H q
17 5 1 homffn ⊢ H Fn B × B
18 17 a1i ⊢ φ → H Fn B × B
19 1 fvexi ⊢ B ∈ V
20 19 a1i ⊢ φ → B ∈ V
21 10 18 20 isssc ⊢ φ → J ⊆ cat H ↔ S ⊆ B ∧ ∀ p ∈ S ∀ q ∈ S p J q ⊆ p H q
22 2 16 21 mpbir2and ⊢ φ → J ⊆ cat H
23 4 oveqd ⊢ φ → x J x = x S × S × ∅ x
24 6 ovconst2 ⊢ x ∈ S ∧ x ∈ S → x S × S × ∅ x = ∅
25 24 anidms ⊢ x ∈ S → x S × S × ∅ x = ∅
26 23 25 sylan9eq ⊢ φ ∧ x ∈ S → x J x = ∅
27 nel02 ⊢ x J x = ∅ → ¬ I ∈ x J x
28 26 27 syl ⊢ φ ∧ x ∈ S → ¬ I ∈ x J x
29 28 reximdva0 ⊢ φ ∧ S ≠ ∅ → ∃ x ∈ S ¬ I ∈ x J x
30 3 29 mpdan ⊢ φ → ∃ x ∈ S ¬ I ∈ x J x
31 rexnal ⊢ ∃ x ∈ S ¬ I ∈ x J x ↔ ¬ ∀ x ∈ S I ∈ x J x
32 30 31 sylib ⊢ φ → ¬ ∀ x ∈ S I ∈ x J x
33 4 oveqd ⊢ φ → x J y = x S × S × ∅ y
34 6 ovconst2 ⊢ x ∈ S ∧ y ∈ S → x S × S × ∅ y = ∅
35 33 34 sylan9eq ⊢ φ ∧ x ∈ S ∧ y ∈ S → x J y = ∅
36 rzal ⊢ x J y = ∅ → ∀ f ∈ x J y ψ
37 35 36 syl ⊢ φ ∧ x ∈ S ∧ y ∈ S → ∀ f ∈ x J y ψ
38 37 ralrimivw ⊢ φ ∧ x ∈ S ∧ y ∈ S → ∀ z ∈ S ∀ f ∈ x J y ψ
39 38 ralrimivva ⊢ φ → ∀ x ∈ S ∀ y ∈ S ∀ z ∈ S ∀ f ∈ x J y ψ
40 32 39 jca ⊢ φ → ¬ ∀ x ∈ S I ∈ x J x ∧ ∀ x ∈ S ∀ y ∈ S ∀ z ∈ S ∀ f ∈ x J y ψ
41 10 22 40 jca32 ⊢ φ → J Fn S × S ∧ J ⊆ cat H ∧ ¬ ∀ x ∈ S I ∈ x J x ∧ ∀ x ∈ S ∀ y ∈ S ∀ z ∈ S ∀ f ∈ x J y ψ