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Theorem isarep1 4928
 Description: Part of a study of the Axiom of Replacement used by the Isabelle prover. The object PrimReplace is apparently the image of the function encoded by φ(x, y) i.e. the class ({⟨x, y⟩ ∣ φ} “ A). If so, we can prove Isabelle's "Axiom of Replacement" conclusion without using the Axiom of Replacement, for which I (N. Megill) currently have no explanation. (Contributed by NM, 26-Oct-2006.) (Proof shortened by Mario Carneiro, 4-Dec-2016.)
Assertion
Ref Expression
isarep1 (𝑏 ({⟨x, y⟩ ∣ φ} “ A) ↔ x A [𝑏 / y]φ)
Distinct variable groups:   x,A   x,𝑏,y
Allowed substitution hints:   φ(x,y,𝑏)   A(y,𝑏)

Proof of Theorem isarep1
Dummy variable z is distinct from all other variables.
StepHypRef Expression
1 vex 2554 . . 3 𝑏 V
21elima 4616 . 2 (𝑏 ({⟨x, y⟩ ∣ φ} “ A) ↔ z A z{⟨x, y⟩ ∣ φ}𝑏)
3 df-br 3756 . . . 4 (z{⟨x, y⟩ ∣ φ}𝑏 ↔ ⟨z, 𝑏 {⟨x, y⟩ ∣ φ})
4 opelopabsb 3988 . . . 4 (⟨z, 𝑏 {⟨x, y⟩ ∣ φ} ↔ [z / x][𝑏 / y]φ)
5 sbsbc 2762 . . . . . 6 ([𝑏 / y]φ[𝑏 / y]φ)
65sbbii 1645 . . . . 5 ([z / x][𝑏 / y]φ ↔ [z / x][𝑏 / y]φ)
7 sbsbc 2762 . . . . 5 ([z / x][𝑏 / y]φ[z / x][𝑏 / y]φ)
86, 7bitr2i 174 . . . 4 ([z / x][𝑏 / y]φ ↔ [z / x][𝑏 / y]φ)
93, 4, 83bitri 195 . . 3 (z{⟨x, y⟩ ∣ φ}𝑏 ↔ [z / x][𝑏 / y]φ)
109rexbii 2325 . 2 (z A z{⟨x, y⟩ ∣ φ}𝑏z A [z / x][𝑏 / y]φ)
11 nfs1v 1812 . . 3 x[z / x][𝑏 / y]φ
12 nfv 1418 . . 3 z[𝑏 / y]φ
13 sbequ12r 1652 . . 3 (z = x → ([z / x][𝑏 / y]φ ↔ [𝑏 / y]φ))
1411, 12, 13cbvrex 2524 . 2 (z A [z / x][𝑏 / y]φx A [𝑏 / y]φ)
152, 10, 143bitri 195 1 (𝑏 ({⟨x, y⟩ ∣ φ} “ A) ↔ x A [𝑏 / y]φ)
 Colors of variables: wff set class Syntax hints:   ↔ wb 98   ∈ wcel 1390  [wsb 1642  ∃wrex 2301  [wsbc 2758  ⟨cop 3370   class class class wbr 3755  {copab 3808   “ cima 4291 This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 99  ax-ia2 100  ax-ia3 101  ax-io 629  ax-5 1333  ax-7 1334  ax-gen 1335  ax-ie1 1379  ax-ie2 1380  ax-8 1392  ax-10 1393  ax-11 1394  ax-i12 1395  ax-bnd 1396  ax-4 1397  ax-14 1402  ax-17 1416  ax-i9 1420  ax-ial 1424  ax-i5r 1425  ax-ext 2019  ax-sep 3866  ax-pow 3918  ax-pr 3935 This theorem depends on definitions:  df-bi 110  df-3an 886  df-tru 1245  df-nf 1347  df-sb 1643  df-eu 1900  df-mo 1901  df-clab 2024  df-cleq 2030  df-clel 2033  df-nfc 2164  df-ral 2305  df-rex 2306  df-v 2553  df-sbc 2759  df-un 2916  df-in 2918  df-ss 2925  df-pw 3353  df-sn 3373  df-pr 3374  df-op 3376  df-br 3756  df-opab 3810  df-xp 4294  df-cnv 4296  df-dm 4298  df-rn 4299  df-res 4300  df-ima 4301 This theorem is referenced by: (None)
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