Theorem axrep6 5239

Description: A condensed form of ax-rep 5231. (Contributed by SN, 18-Sep-2023.) (Proof shortened by Matthew House, 18-Sep-2025.)

Assertion

Ref	Expression
axrep6	⊢ (∀𝑤∃*𝑧𝜑 → ∃𝑦∀𝑧(𝑧 ∈ 𝑦 ↔ ∃𝑤 ∈ 𝑥 𝜑))

Distinct variable groups:   𝑥,𝑤,𝑦,𝑧   𝜑,𝑦

Allowed substitution hints:   𝜑(𝑥, 𝑧, 𝑤)

Proof of Theorem axrep6

Step	Hyp	Ref	Expression
1		axrep4v 5236	. 2 ⊢ (∀𝑤∃𝑦∀𝑧(𝜑 → 𝑧 = 𝑦) → ∃𝑦∀𝑧(𝑧 ∈ 𝑦 ↔ ∃𝑤(𝑤 ∈ 𝑥 ∧ 𝜑)))
2		dfmo 2565	. . 3 ⊢ (∃*𝑧𝜑 ↔ ∃𝑦∀𝑧(𝜑 → 𝑧 = 𝑦))
3	2	albii 1851	. 2 ⊢ (∀𝑤∃*𝑧𝜑 ↔ ∀𝑤∃𝑦∀𝑧(𝜑 → 𝑧 = 𝑦))
4		df-rex 3087	. . . . 5 ⊢ (∃𝑤 ∈ 𝑥 𝜑 ↔ ∃𝑤(𝑤 ∈ 𝑥 ∧ 𝜑))
5	4	bibi2i 340	. . . 4 ⊢ ((𝑧 ∈ 𝑦 ↔ ∃𝑤 ∈ 𝑥 𝜑) ↔ (𝑧 ∈ 𝑦 ↔ ∃𝑤(𝑤 ∈ 𝑥 ∧ 𝜑)))
6	5	albii 1851	. . 3 ⊢ (∀𝑧(𝑧 ∈ 𝑦 ↔ ∃𝑤 ∈ 𝑥 𝜑) ↔ ∀𝑧(𝑧 ∈ 𝑦 ↔ ∃𝑤(𝑤 ∈ 𝑥 ∧ 𝜑)))
7	6	exbii 1880	. 2 ⊢ (∃𝑦∀𝑧(𝑧 ∈ 𝑦 ↔ ∃𝑤 ∈ 𝑥 𝜑) ↔ ∃𝑦∀𝑧(𝑧 ∈ 𝑦 ↔ ∃𝑤(𝑤 ∈ 𝑥 ∧ 𝜑)))
8	1, 3, 7	3imtr4i 295	1 ⊢ (∀𝑤∃*𝑧𝜑 → ∃𝑦∀𝑧(𝑧 ∈ 𝑦 ↔ ∃𝑤 ∈ 𝑥 𝜑))

This proof depends on syntax axioms:   → wi 4   ↔ wb 209   ∧ wa 401  ∀wal 1567  ∃wex 1811  ∃*wmo 2562  ∃wrex 3086

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1827  ax-4 1841  ax-5 1942  ax-6 1999  ax-7 2040  ax-rep 5231

This proof depends on definitions:  df-bi 210  df-an 402  df-ex 1812  df-mo 2564  df-rex 3087

This theorem is used by:  zfrep6  5241  axrep6g  5242  axsepgfromrep  5246  bj-rep  38081  sn-axrep5v  43364  sn-axprlem3  43365