Metamath Proof Explorer


Theorem ustuqtop5

Description: Lemma for ustuqtop . (Contributed by Thierry Arnoux, 11-Jan-2018)

Ref Expression
Hypothesis utopustuq.1 ⊢ N = p ∈ X ⟼ ran ⁡ v ∈ U ⟼ v p
Assertion ustuqtop5 ⊢ U ∈ UnifOn ⁡ X ∧ p ∈ X → X ∈ N ⁡ p

Proof

Step Hyp Ref Expression
1 utopustuq.1 ⊢ N = p ∈ X ⟼ ran ⁡ v ∈ U ⟼ v p
2 ustbasel ⊢ U ∈ UnifOn ⁡ X → X × X ∈ U
3 snssi ⊢ p ∈ X → p ⊆ X
4 dfss ⊢ p ⊆ X ↔ p = p ∩ X
5 3 4 sylib ⊢ p ∈ X → p = p ∩ X
6 incom ⊢ p ∩ X = X ∩ p
7 5 6 eqtr2di ⊢ p ∈ X → X ∩ p = p
8 snnzg ⊢ p ∈ X → p ≠ ∅
9 7 8 eqnetrd ⊢ p ∈ X → X ∩ p ≠ ∅
10 9 adantl ⊢ U ∈ UnifOn ⁡ X ∧ p ∈ X → X ∩ p ≠ ∅
11 xpima2 ⊢ X ∩ p ≠ ∅ → X × X p = X
12 10 11 syl ⊢ U ∈ UnifOn ⁡ X ∧ p ∈ X → X × X p = X
13 12 eqcomd ⊢ U ∈ UnifOn ⁡ X ∧ p ∈ X → X = X × X p
14 imaeq1 ⊢ w = X × X → w p = X × X p
15 14 rspceeqv ⊢ X × X ∈ U ∧ X = X × X p → ∃ w ∈ U X = w p
16 2 13 15 syl2an2r ⊢ U ∈ UnifOn ⁡ X ∧ p ∈ X → ∃ w ∈ U X = w p
17 elfvex ⊢ U ∈ UnifOn ⁡ X → X ∈ V
18 1 ustuqtoplem ⊢ U ∈ UnifOn ⁡ X ∧ p ∈ X ∧ X ∈ V → X ∈ N ⁡ p ↔ ∃ w ∈ U X = w p
19 17 18 mpidan ⊢ U ∈ UnifOn ⁡ X ∧ p ∈ X → X ∈ N ⁡ p ↔ ∃ w ∈ U X = w p
20 16 19 mpbird ⊢ U ∈ UnifOn ⁡ X ∧ p ∈ X → X ∈ N ⁡ p