Metamath Proof Explorer


Theorem bnj864

Description: Technical lemma for bnj69 . This lemma may no longer be used or have become an indirect lemma of the theorem in question (i.e. a lemma of a lemma... of the theorem). (Contributed by Jonathan Ben-Naim, 3-Jun-2011) (New usage is discouraged.)

Ref Expression
Hypotheses bnj864.1 ⊢ φ ↔ f ⁡ ∅ = pred X A R
bnj864.2 ⊢ ψ ↔ ∀ i ∈ ω suc ⁡ i ∈ n → f ⁡ suc ⁡ i = ⋃ y ∈ f ⁡ i pred y A R
bnj864.3 ⊢ D = ω ∖ ∅
bnj864.4 ⊢ χ ↔ R FrSe A ∧ X ∈ A ∧ n ∈ D
bnj864.5 ⊢ θ ↔ f Fn n ∧ φ ∧ ψ
Assertion bnj864 ⊢ χ → ∃! f θ

Proof

Step Hyp Ref Expression
1 bnj864.1 ⊢ φ ↔ f ⁡ ∅ = pred X A R
2 bnj864.2 ⊢ ψ ↔ ∀ i ∈ ω suc ⁡ i ∈ n → f ⁡ suc ⁡ i = ⋃ y ∈ f ⁡ i pred y A R
3 bnj864.3 ⊢ D = ω ∖ ∅
4 bnj864.4 ⊢ χ ↔ R FrSe A ∧ X ∈ A ∧ n ∈ D
5 bnj864.5 ⊢ θ ↔ f Fn n ∧ φ ∧ ψ
6 1 2 3 bnj852 ⊢ R FrSe A ∧ X ∈ A → ∀ n ∈ D ∃! f f Fn n ∧ φ ∧ ψ
7 df-ral ⊢ ∀ n ∈ D ∃! f f Fn n ∧ φ ∧ ψ ↔ ∀ n n ∈ D → ∃! f f Fn n ∧ φ ∧ ψ
8 7 imbi2i ⊢ R FrSe A ∧ X ∈ A → ∀ n ∈ D ∃! f f Fn n ∧ φ ∧ ψ ↔ R FrSe A ∧ X ∈ A → ∀ n n ∈ D → ∃! f f Fn n ∧ φ ∧ ψ
9 19.21v ⊢ ∀ n R FrSe A ∧ X ∈ A → n ∈ D → ∃! f f Fn n ∧ φ ∧ ψ ↔ R FrSe A ∧ X ∈ A → ∀ n n ∈ D → ∃! f f Fn n ∧ φ ∧ ψ
10 impexp ⊢ R FrSe A ∧ X ∈ A ∧ n ∈ D → ∃! f f Fn n ∧ φ ∧ ψ ↔ R FrSe A ∧ X ∈ A → n ∈ D → ∃! f f Fn n ∧ φ ∧ ψ
11 df-3an ⊢ R FrSe A ∧ X ∈ A ∧ n ∈ D ↔ R FrSe A ∧ X ∈ A ∧ n ∈ D
12 11 bicomi ⊢ R FrSe A ∧ X ∈ A ∧ n ∈ D ↔ R FrSe A ∧ X ∈ A ∧ n ∈ D
13 12 imbi1i ⊢ R FrSe A ∧ X ∈ A ∧ n ∈ D → ∃! f f Fn n ∧ φ ∧ ψ ↔ R FrSe A ∧ X ∈ A ∧ n ∈ D → ∃! f f Fn n ∧ φ ∧ ψ
14 10 13 bitr3i ⊢ R FrSe A ∧ X ∈ A → n ∈ D → ∃! f f Fn n ∧ φ ∧ ψ ↔ R FrSe A ∧ X ∈ A ∧ n ∈ D → ∃! f f Fn n ∧ φ ∧ ψ
15 14 albii ⊢ ∀ n R FrSe A ∧ X ∈ A → n ∈ D → ∃! f f Fn n ∧ φ ∧ ψ ↔ ∀ n R FrSe A ∧ X ∈ A ∧ n ∈ D → ∃! f f Fn n ∧ φ ∧ ψ
16 8 9 15 3bitr2i ⊢ R FrSe A ∧ X ∈ A → ∀ n ∈ D ∃! f f Fn n ∧ φ ∧ ψ ↔ ∀ n R FrSe A ∧ X ∈ A ∧ n ∈ D → ∃! f f Fn n ∧ φ ∧ ψ
17 6 16 mpbi ⊢ ∀ n R FrSe A ∧ X ∈ A ∧ n ∈ D → ∃! f f Fn n ∧ φ ∧ ψ
18 17 spi ⊢ R FrSe A ∧ X ∈ A ∧ n ∈ D → ∃! f f Fn n ∧ φ ∧ ψ
19 5 eubii ⊢ ∃! f θ ↔ ∃! f f Fn n ∧ φ ∧ ψ
20 18 4 19 3imtr4i ⊢ χ → ∃! f θ