Metamath Proof Explorer


Theorem bnj1049

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 bnj1049.1 ⊢ ζ ↔ i ∈ n ∧ z ∈ f ⁡ i
bnj1049.2 ⊢ η ↔ θ ∧ τ ∧ χ ∧ ζ → z ∈ B
Assertion bnj1049 ⊢ ∀ i ∈ n η ↔ ∀ i η

Proof

Step Hyp Ref Expression
1 bnj1049.1 ⊢ ζ ↔ i ∈ n ∧ z ∈ f ⁡ i
2 bnj1049.2 ⊢ η ↔ θ ∧ τ ∧ χ ∧ ζ → z ∈ B
3 df-ral ⊢ ∀ i ∈ n η ↔ ∀ i i ∈ n → η
4 2 imbi2i ⊢ i ∈ n → η ↔ i ∈ n → θ ∧ τ ∧ χ ∧ ζ → z ∈ B
5 impexp ⊢ i ∈ n ∧ θ ∧ τ ∧ χ ∧ ζ → z ∈ B ↔ i ∈ n → θ ∧ τ ∧ χ ∧ ζ → z ∈ B
6 4 5 bitr4i ⊢ i ∈ n → η ↔ i ∈ n ∧ θ ∧ τ ∧ χ ∧ ζ → z ∈ B
7 1 simplbi ⊢ ζ → i ∈ n
8 7 bnj708 ⊢ θ ∧ τ ∧ χ ∧ ζ → i ∈ n
9 8 pm4.71ri ⊢ θ ∧ τ ∧ χ ∧ ζ ↔ i ∈ n ∧ θ ∧ τ ∧ χ ∧ ζ
10 9 bicomi ⊢ i ∈ n ∧ θ ∧ τ ∧ χ ∧ ζ ↔ θ ∧ τ ∧ χ ∧ ζ
11 10 imbi1i ⊢ i ∈ n ∧ θ ∧ τ ∧ χ ∧ ζ → z ∈ B ↔ θ ∧ τ ∧ χ ∧ ζ → z ∈ B
12 6 11 bitri ⊢ i ∈ n → η ↔ θ ∧ τ ∧ χ ∧ ζ → z ∈ B
13 12 2 bitr4i ⊢ i ∈ n → η ↔ η
14 13 albii ⊢ ∀ i i ∈ n → η ↔ ∀ i η
15 3 14 bitri ⊢ ∀ i ∈ n η ↔ ∀ i η