Metamath Proof Explorer


Theorem resnonrel

Description: A restriction of the non-relation part of a class is empty. (Contributed by RP, 22-Oct-2020)

Ref Expression
Assertion resnonrel ⊢ A ∖ A -1 -1 ↾ B = ∅

Proof

Step Hyp Ref Expression
1 ssv ⊢ B ⊆ V
2 ssres2 ⊢ B ⊆ V → A ∖ A -1 -1 ↾ B ⊆ A ∖ A -1 -1 ↾ V
3 1 2 ax-mp ⊢ A ∖ A -1 -1 ↾ B ⊆ A ∖ A -1 -1 ↾ V
4 cnvnonrel ⊢ A ∖ A -1 -1 -1 = ∅
5 4 cnveqi ⊢ A ∖ A -1 -1 -1 -1 = ∅ -1
6 cnvcnv2 ⊢ A ∖ A -1 -1 -1 -1 = A ∖ A -1 -1 ↾ V
7 cnv0 ⊢ ∅ -1 = ∅
8 5 6 7 3eqtr3i ⊢ A ∖ A -1 -1 ↾ V = ∅
9 3 8 sseqtri ⊢ A ∖ A -1 -1 ↾ B ⊆ ∅
10 ss0b ⊢ A ∖ A -1 -1 ↾ B ⊆ ∅ ↔ A ∖ A -1 -1 ↾ B = ∅
11 9 10 mpbi ⊢ A ∖ A -1 -1 ↾ B = ∅