Theorem enfiALT 9124

Description: Shorter proof of enfi 9123 using ax-pow 5312. (Contributed by NM, 22-Aug-2008.) (Proof modification is discouraged.) (New usage is discouraged.)

Assertion

Ref	Expression
enfiALT	⊢ (𝐴 ≈ 𝐵 → (𝐴 ∈ Fin ↔ 𝐵 ∈ Fin))

Proof of Theorem enfiALT

Dummy variable 𝑥 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		enen1 9057	. . 3 ⊢ (𝐴 ≈ 𝐵 → (𝐴 ≈ 𝑥 ↔ 𝐵 ≈ 𝑥))
2	1	rexbidv 3162	. 2 ⊢ (𝐴 ≈ 𝐵 → (∃𝑥 ∈ ω 𝐴 ≈ 𝑥 ↔ ∃𝑥 ∈ ω 𝐵 ≈ 𝑥))
3		isfi 8924	. 2 ⊢ (𝐴 ∈ Fin ↔ ∃𝑥 ∈ ω 𝐴 ≈ 𝑥)
4		isfi 8924	. 2 ⊢ (𝐵 ∈ Fin ↔ ∃𝑥 ∈ ω 𝐵 ≈ 𝑥)
5	2, 3, 4	3bitr4g 314	1 ⊢ (𝐴 ≈ 𝐵 → (𝐴 ∈ Fin ↔ 𝐵 ∈ Fin))

Syntax hints:   → wi 4   ↔ wb 206   ∈ wcel 2114  ∃wrex 3062   class class class wbr 5100  ωcom 7818   ≈ cen 8892  Fincfn 8895

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1797  ax-4 1811  ax-5 1912  ax-6 1969  ax-7 2010  ax-8 2116  ax-9 2124  ax-10 2147  ax-11 2163  ax-12 2185  ax-ext 2709  ax-sep 5243  ax-pow 5312  ax-pr 5379  ax-un 7690

This theorem depends on definitions:  df-bi 207  df-an 396  df-or 849  df-3an 1089  df-tru 1545  df-fal 1555  df-ex 1782  df-nf 1786  df-sb 2069  df-mo 2540  df-eu 2570  df-clab 2716  df-cleq 2729  df-clel 2812  df-nfc 2886  df-ral 3053  df-rex 3063  df-rab 3402  df-v 3444  df-dif 3906  df-un 3908  df-in 3910  df-ss 3920  df-nul 4288  df-if 4482  df-pw 4558  df-sn 4583  df-pr 4585  df-op 4589  df-uni 4866  df-br 5101  df-opab 5163  df-id 5527  df-xp 5638  df-rel 5639  df-cnv 5640  df-co 5641  df-dm 5642  df-rn 5643  df-res 5644  df-ima 5645  df-fun 6502  df-fn 6503  df-f 6504  df-f1 6505  df-fo 6506  df-f1o 6507  df-er 8645  df-en 8896  df-fin 8899

This theorem is referenced by: (None)