Metamath Proof Explorer


Theorem undisjrab

Description: Union of two disjoint restricted class abstractions; compare unrab . (Contributed by Steve Rodriguez, 28-Feb-2020)

Ref Expression
Assertion undisjrab x A | φ x A | ψ = x A | φ x A | ψ = x A | φ ψ

Proof

Step Hyp Ref Expression
1 rabeq0 x A | φ ψ = x A ¬ φ ψ
2 df-nan φ ψ ¬ φ ψ
3 nanorxor φ ψ φ ψ φ ψ
4 2 3 bitr3i ¬ φ ψ φ ψ φ ψ
5 4 ralbii x A ¬ φ ψ x A φ ψ φ ψ
6 rabbi x A φ ψ φ ψ x A | φ ψ = x A | φ ψ
7 1 5 6 3bitri x A | φ ψ = x A | φ ψ = x A | φ ψ
8 inrab x A | φ x A | ψ = x A | φ ψ
9 8 eqeq1i x A | φ x A | ψ = x A | φ ψ =
10 unrab x A | φ x A | ψ = x A | φ ψ
11 10 eqeq1i x A | φ x A | ψ = x A | φ ψ x A | φ ψ = x A | φ ψ
12 7 9 11 3bitr4i x A | φ x A | ψ = x A | φ x A | ψ = x A | φ ψ