Metamath Proof Explorer


Theorem rexlimdv3d

Description: An extended version of rexlimdvv to include three set variables. (Contributed by Igor Ieskov, 21-Jan-2024)

Ref Expression
Hypothesis rexlimdv3d.1 ⊢ φ → x ∈ A ∧ y ∈ B ∧ z ∈ C → ψ → χ
Assertion rexlimdv3d ⊢ φ → ∃ x ∈ A ∃ y ∈ B ∃ z ∈ C ψ → χ

Proof

Step Hyp Ref Expression
1 rexlimdv3d.1 ⊢ φ → x ∈ A ∧ y ∈ B ∧ z ∈ C → ψ → χ
2 1 3expd ⊢ φ → x ∈ A → y ∈ B → z ∈ C → ψ → χ
3 2 imp4d ⊢ φ → x ∈ A ∧ y ∈ B ∧ z ∈ C → ψ → χ
4 3 expdimp ⊢ φ ∧ x ∈ A → y ∈ B ∧ z ∈ C → ψ → χ
5 4 rexlimdvv ⊢ φ ∧ x ∈ A → ∃ y ∈ B ∃ z ∈ C ψ → χ
6 5 rexlimdva ⊢ φ → ∃ x ∈ A ∃ y ∈ B ∃ z ∈ C ψ → χ