Theorem nfoprab3 5549

Description: The abstraction variables in an operation class abstraction are not free. (Contributed by NM, 22-Aug-2013.)

Assertion

Ref	Expression
nfoprab3	⊢ Ⅎz{⟨⟨x, y⟩, z⟩ ∣ φ}

Proof of Theorem nfoprab3

Dummy variable w is distinct from all other variables.

Step	Hyp	Ref	Expression
1		df-oprab 5529	. 2 ⊢ {⟨⟨x, y⟩, z⟩ ∣ φ} = {w ∣ ∃x∃y∃z(w = ⟨⟨x, y⟩, z⟩ ∧ φ)}
2		nfe1 1732	. . . . 5 ⊢ Ⅎz∃z(w = ⟨⟨x, y⟩, z⟩ ∧ φ)
3	2	nfex 1843	. . . 4 ⊢ Ⅎz∃y∃z(w = ⟨⟨x, y⟩, z⟩ ∧ φ)
4	3	nfex 1843	. . 3 ⊢ Ⅎz∃x∃y∃z(w = ⟨⟨x, y⟩, z⟩ ∧ φ)
5	4	nfab 2494	. 2 ⊢ Ⅎz{w ∣ ∃x∃y∃z(w = ⟨⟨x, y⟩, z⟩ ∧ φ)}
6	1, 5	nfcxfr 2487	1 ⊢ Ⅎz{⟨⟨x, y⟩, z⟩ ∣ φ}

This proof depends on syntax axioms:   ∧ wa 358  ∃wex 1541   = wceq 1642  {cab 2339  Ⅎwnfc 2477  ⟨cop 4562  {coprab 5528

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1546  ax-5 1557  ax-17 1616  ax-9 1654  ax-8 1675  ax-6 1729  ax-7 1734  ax-11 1746  ax-12 1925  ax-ext 2334

This proof depends on definitions:  df-bi 177  df-an 360  df-tru 1319  df-ex 1542  df-nf 1545  df-sb 1649  df-clab 2340  df-cleq 2346  df-clel 2349  df-nfc 2479  df-oprab 5529

This theorem is used by:  ov3  5600