Theorem nfmpt 3878

Description: Bound-variable hypothesis builder for the maps-to notation. (Contributed by NM, 20-Feb-2013.)

Hypotheses

Ref	Expression
nfmpt.1	⊢ Ⅎ𝑥𝐴
nfmpt.2	⊢ Ⅎ𝑥𝐵

Assertion

Ref	Expression
nfmpt	⊢ Ⅎ𝑥(𝑦 ∈ 𝐴 ↦ 𝐵)

Distinct variable group:   𝑥,𝑦

Allowed substitution hints:   𝐴(𝑥,𝑦)   𝐵(𝑥,𝑦)

Proof of Theorem nfmpt

Dummy variable 𝑧 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		df-mpt 3849	. 2 ⊢ (𝑦 ∈ 𝐴 ↦ 𝐵) = {⟨𝑦, 𝑧⟩ ∣ (𝑦 ∈ 𝐴 ∧ 𝑧 = 𝐵)}
2		nfmpt.1	. . . . 5 ⊢ Ⅎ𝑥𝐴
3	2	nfcri 2214	. . . 4 ⊢ Ⅎ𝑥 𝑦 ∈ 𝐴
4		nfmpt.2	. . . . 5 ⊢ Ⅎ𝑥𝐵
5	4	nfeq2 2231	. . . 4 ⊢ Ⅎ𝑥 𝑧 = 𝐵
6	3, 5	nfan 1498	. . 3 ⊢ Ⅎ𝑥(𝑦 ∈ 𝐴 ∧ 𝑧 = 𝐵)
7	6	nfopab 3854	. 2 ⊢ Ⅎ𝑥{⟨𝑦, 𝑧⟩ ∣ (𝑦 ∈ 𝐴 ∧ 𝑧 = 𝐵)}
8	1, 7	nfcxfr 2217	1 ⊢ Ⅎ𝑥(𝑦 ∈ 𝐴 ↦ 𝐵)

Syntax hints:   ∧ wa 102   = wceq 1285   ∈ wcel 1434  Ⅎwnfc 2207  {copab 3846   ↦ cmpt 3847

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 104  ax-ia2 105  ax-ia3 106  ax-io 663  ax-5 1377  ax-7 1378  ax-gen 1379  ax-ie1 1423  ax-ie2 1424  ax-8 1436  ax-10 1437  ax-11 1438  ax-i12 1439  ax-bndl 1440  ax-4 1441  ax-17 1460  ax-i9 1464  ax-ial 1468  ax-i5r 1469  ax-ext 2064

This theorem depends on definitions:  df-bi 115  df-tru 1288  df-nf 1391  df-sb 1687  df-clab 2069  df-cleq 2075  df-clel 2078  df-nfc 2209  df-opab 3848  df-mpt 3849

This theorem is referenced by:  nffrec  6045  nfsum1  10331  nfsum  10332