Theorem bnj934 32894

Description: Technical lemma for bnj69 32969. 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.)

Hypotheses

Ref	Expression
bnj934.1	⊢ (𝜑 ↔ (𝑓‘∅) = pred(𝑋, 𝐴, 𝑅))
bnj934.4	⊢ (𝜑′ ↔ [𝑝 / 𝑛]𝜑)
bnj934.7	⊢ (𝜑″ ↔ [𝐺 / 𝑓]𝜑′)
bnj934.50	⊢ 𝐺 ∈ V

Assertion

Ref	Expression
bnj934	⊢ ((𝜑 ∧ (𝐺‘∅) = (𝑓‘∅)) → 𝜑″)

Distinct variable groups:   𝐴,𝑓,𝑛   𝑅,𝑓,𝑛   𝑓,𝑋,𝑛

Allowed substitution hints:   𝜑(𝑓,𝑛,𝑝)   𝐴(𝑝)   𝑅(𝑝)   𝐺(𝑓,𝑛,𝑝)   𝑋(𝑝)   𝜑′(𝑓,𝑛,𝑝)   𝜑″(𝑓,𝑛,𝑝)

Proof of Theorem bnj934

Step	Hyp	Ref	Expression
1		bnj934.1	. . . 4 ⊢ (𝜑 ↔ (𝑓‘∅) = pred(𝑋, 𝐴, 𝑅))
2		eqtr 2762	. . . 4 ⊢ (((𝐺‘∅) = (𝑓‘∅) ∧ (𝑓‘∅) = pred(𝑋, 𝐴, 𝑅)) → (𝐺‘∅) = pred(𝑋, 𝐴, 𝑅))
3	1, 2	sylan2b 593	. . 3 ⊢ (((𝐺‘∅) = (𝑓‘∅) ∧ 𝜑) → (𝐺‘∅) = pred(𝑋, 𝐴, 𝑅))
4		bnj934.7	. . . . 5 ⊢ (𝜑″ ↔ [𝐺 / 𝑓]𝜑′)
5		bnj934.4	. . . . . . . 8 ⊢ (𝜑′ ↔ [𝑝 / 𝑛]𝜑)
6		vex 3434	. . . . . . . 8 ⊢ 𝑝 ∈ V
7	1, 5, 6	bnj523 32846	. . . . . . 7 ⊢ (𝜑′ ↔ (𝑓‘∅) = pred(𝑋, 𝐴, 𝑅))
8	7, 1	bitr4i 277	. . . . . 6 ⊢ (𝜑′ ↔ 𝜑)
9	8	sbcbii 3780	. . . . 5 ⊢ ([𝐺 / 𝑓]𝜑′ ↔ [𝐺 / 𝑓]𝜑)
10	4, 9	bitri 274	. . . 4 ⊢ (𝜑″ ↔ [𝐺 / 𝑓]𝜑)
11		bnj934.50	. . . 4 ⊢ 𝐺 ∈ V
12	1, 10, 11	bnj609 32876	. . 3 ⊢ (𝜑″ ↔ (𝐺‘∅) = pred(𝑋, 𝐴, 𝑅))
13	3, 12	sylibr 233	. 2 ⊢ (((𝐺‘∅) = (𝑓‘∅) ∧ 𝜑) → 𝜑″)
14	13	ancoms 458	1 ⊢ ((𝜑 ∧ (𝐺‘∅) = (𝑓‘∅)) → 𝜑″)

Syntax hints:   → wi 4   ↔ wb 205   ∧ wa 395   = wceq 1541   ∈ wcel 2109  Vcvv 3430  [wsbc 3719  ∅c0 4261  ‘cfv 6430   predc-bnj14 32646

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1801  ax-4 1815  ax-5 1916  ax-6 1974  ax-7 2014  ax-8 2111  ax-9 2119  ax-ext 2710

This theorem depends on definitions:  df-bi 206  df-an 396  df-tru 1544  df-ex 1786  df-sb 2071  df-clab 2717  df-cleq 2731  df-clel 2817  df-v 3432  df-sbc 3720  df-in 3898  df-ss 3908  df-uni 4845  df-br 5079  df-iota 6388  df-fv 6438

This theorem is referenced by:  bnj929  32895