Metamath Proof Explorer


Theorem faeval

Description: Value of the 'almost everywhere' relation for a given relation and measure. (Contributed by Thierry Arnoux, 22-Oct-2017)

Ref Expression
Assertion faeval ⊢ R ∈ V ∧ M ∈ ⋃ ran ⁡ measures → R ~ae M = f g | f ∈ dom ⁡ R ⋃ dom ⁡ M ∧ g ∈ dom ⁡ R ⋃ dom ⁡ M ∧ x ∈ ⋃ dom ⁡ M | f ⁡ x R g ⁡ x M-ae.

Proof

Step Hyp Ref Expression
1 simpl ⊢ r = R ∧ m = M → r = R
2 1 dmeqd ⊢ r = R ∧ m = M → dom ⁡ r = dom ⁡ R
3 simpr ⊢ r = R ∧ m = M → m = M
4 3 dmeqd ⊢ r = R ∧ m = M → dom ⁡ m = dom ⁡ M
5 4 unieqd ⊢ r = R ∧ m = M → ⋃ dom ⁡ m = ⋃ dom ⁡ M
6 2 5 oveq12d ⊢ r = R ∧ m = M → dom ⁡ r ⋃ dom ⁡ m = dom ⁡ R ⋃ dom ⁡ M
7 6 eleq2d ⊢ r = R ∧ m = M → f ∈ dom ⁡ r ⋃ dom ⁡ m ↔ f ∈ dom ⁡ R ⋃ dom ⁡ M
8 6 eleq2d ⊢ r = R ∧ m = M → g ∈ dom ⁡ r ⋃ dom ⁡ m ↔ g ∈ dom ⁡ R ⋃ dom ⁡ M
9 7 8 anbi12d ⊢ r = R ∧ m = M → f ∈ dom ⁡ r ⋃ dom ⁡ m ∧ g ∈ dom ⁡ r ⋃ dom ⁡ m ↔ f ∈ dom ⁡ R ⋃ dom ⁡ M ∧ g ∈ dom ⁡ R ⋃ dom ⁡ M
10 1 breqd ⊢ r = R ∧ m = M → f ⁡ x r g ⁡ x ↔ f ⁡ x R g ⁡ x
11 5 10 rabeqbidv ⊢ r = R ∧ m = M → x ∈ ⋃ dom ⁡ m | f ⁡ x r g ⁡ x = x ∈ ⋃ dom ⁡ M | f ⁡ x R g ⁡ x
12 11 3 breq12d ⊢ r = R ∧ m = M → x ∈ ⋃ dom ⁡ m | f ⁡ x r g ⁡ x m-ae. ↔ x ∈ ⋃ dom ⁡ M | f ⁡ x R g ⁡ x M-ae.
13 9 12 anbi12d ⊢ r = R ∧ m = M → f ∈ dom ⁡ r ⋃ dom ⁡ m ∧ g ∈ dom ⁡ r ⋃ dom ⁡ m ∧ x ∈ ⋃ dom ⁡ m | f ⁡ x r g ⁡ x m-ae. ↔ f ∈ dom ⁡ R ⋃ dom ⁡ M ∧ g ∈ dom ⁡ R ⋃ dom ⁡ M ∧ x ∈ ⋃ dom ⁡ M | f ⁡ x R g ⁡ x M-ae.
14 13 opabbidv ⊢ r = R ∧ m = M → f g | f ∈ dom ⁡ r ⋃ dom ⁡ m ∧ g ∈ dom ⁡ r ⋃ dom ⁡ m ∧ x ∈ ⋃ dom ⁡ m | f ⁡ x r g ⁡ x m-ae. = f g | f ∈ dom ⁡ R ⋃ dom ⁡ M ∧ g ∈ dom ⁡ R ⋃ dom ⁡ M ∧ x ∈ ⋃ dom ⁡ M | f ⁡ x R g ⁡ x M-ae.
15 df-fae ⊢ ~ae = r ∈ V , m ∈ ⋃ ran ⁡ measures ⟼ f g | f ∈ dom ⁡ r ⋃ dom ⁡ m ∧ g ∈ dom ⁡ r ⋃ dom ⁡ m ∧ x ∈ ⋃ dom ⁡ m | f ⁡ x r g ⁡ x m-ae.
16 ovex ⊢ dom ⁡ R ⋃ dom ⁡ M ∈ V
17 16 16 xpex ⊢ dom ⁡ R ⋃ dom ⁡ M × dom ⁡ R ⋃ dom ⁡ M ∈ V
18 opabssxp ⊢ f g | f ∈ dom ⁡ R ⋃ dom ⁡ M ∧ g ∈ dom ⁡ R ⋃ dom ⁡ M ∧ x ∈ ⋃ dom ⁡ M | f ⁡ x R g ⁡ x M-ae. ⊆ dom ⁡ R ⋃ dom ⁡ M × dom ⁡ R ⋃ dom ⁡ M
19 17 18 ssexi ⊢ f g | f ∈ dom ⁡ R ⋃ dom ⁡ M ∧ g ∈ dom ⁡ R ⋃ dom ⁡ M ∧ x ∈ ⋃ dom ⁡ M | f ⁡ x R g ⁡ x M-ae. ∈ V
20 14 15 19 ovmpoa ⊢ R ∈ V ∧ M ∈ ⋃ ran ⁡ measures → R ~ae M = f g | f ∈ dom ⁡ R ⋃ dom ⁡ M ∧ g ∈ dom ⁡ R ⋃ dom ⁡ M ∧ x ∈ ⋃ dom ⁡ M | f ⁡ x R g ⁡ x M-ae.