Theorem nfdfat 43320

Description: Bound-variable hypothesis builder for "defined at". To prove a deduction version of this theorem is not easily possible because many deduction versions for bound-variable hypothesis builder for constructs the definition of "defined at" is based on are not available (e.g., for Fun/Rel, dom, ⊆, etc.). (Contributed by Alexander van der Vekens, 26-May-2017.)

Hypotheses

Ref	Expression
nfdfat.1	⊢ Ⅎ𝑥𝐹
nfdfat.2	⊢ Ⅎ𝑥𝐴

Assertion

Ref	Expression
nfdfat	⊢ Ⅎ𝑥 𝐹 defAt 𝐴

Proof of Theorem nfdfat

Step	Hyp	Ref	Expression
1		df-dfat 43312	. 2 ⊢ (𝐹 defAt 𝐴 ↔ (𝐴 ∈ dom 𝐹 ∧ Fun (𝐹 ↾ {𝐴})))
2		nfdfat.2	. . . 4 ⊢ Ⅎ𝑥𝐴
3		nfdfat.1	. . . . 5 ⊢ Ⅎ𝑥𝐹
4	3	nfdm 5817	. . . 4 ⊢ Ⅎ𝑥dom 𝐹
5	2, 4	nfel 2992	. . 3 ⊢ Ⅎ𝑥 𝐴 ∈ dom 𝐹
6	2	nfsn 4636	. . . . 5 ⊢ Ⅎ𝑥{𝐴}
7	3, 6	nfres 5849	. . . 4 ⊢ Ⅎ𝑥(𝐹 ↾ {𝐴})
8	7	nffun 6372	. . 3 ⊢ Ⅎ𝑥Fun (𝐹 ↾ {𝐴})
9	5, 8	nfan 1896	. 2 ⊢ Ⅎ𝑥(𝐴 ∈ dom 𝐹 ∧ Fun (𝐹 ↾ {𝐴}))
10	1, 9	nfxfr 1849	1 ⊢ Ⅎ𝑥 𝐹 defAt 𝐴

Syntax hints:   ∧ wa 398  Ⅎwnf 1780   ∈ wcel 2110  Ⅎwnfc 2961  {csn 4560  dom cdm 5549   ↾ cres 5551  Fun wfun 6343   defAt wdfat 43309

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1792  ax-4 1806  ax-5 1907  ax-6 1966  ax-7 2011  ax-8 2112  ax-9 2120  ax-10 2141  ax-11 2157  ax-12 2173  ax-ext 2793

This theorem depends on definitions:  df-bi 209  df-an 399  df-or 844  df-3an 1085  df-tru 1536  df-ex 1777  df-nf 1781  df-sb 2066  df-clab 2800  df-cleq 2814  df-clel 2893  df-nfc 2963  df-ral 3143  df-rab 3147  df-v 3496  df-dif 3938  df-un 3940  df-in 3942  df-ss 3951  df-nul 4291  df-if 4467  df-sn 4561  df-pr 4563  df-op 4567  df-br 5059  df-opab 5121  df-xp 5555  df-rel 5556  df-cnv 5557  df-co 5558  df-dm 5559  df-res 5561  df-fun 6351  df-dfat 43312

This theorem is referenced by:  nfafv  43329  nfafv2  43411