MPE Home Metamath Proof Explorer < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  MPE Home  >  Th. List  >  eqfnfv3 Structured version   Visualization version   GIF version

Theorem eqfnfv3 6221
Description: Derive equality of functions from equality of their values. (Contributed by Jeff Madsen, 2-Sep-2009.)
Assertion
Ref Expression
eqfnfv3 ((𝐹 Fn 𝐴𝐺 Fn 𝐵) → (𝐹 = 𝐺 ↔ (𝐵𝐴 ∧ ∀𝑥𝐴 (𝑥𝐵 ∧ (𝐹𝑥) = (𝐺𝑥)))))
Distinct variable groups:   𝑥,𝐴   𝑥,𝐹   𝑥,𝐺   𝑥,𝐵

Proof of Theorem eqfnfv3
StepHypRef Expression
1 eqfnfv2 6220 . 2 ((𝐹 Fn 𝐴𝐺 Fn 𝐵) → (𝐹 = 𝐺 ↔ (𝐴 = 𝐵 ∧ ∀𝑥𝐴 (𝐹𝑥) = (𝐺𝑥))))
2 eqss 3583 . . . . 5 (𝐴 = 𝐵 ↔ (𝐴𝐵𝐵𝐴))
3 ancom 465 . . . . 5 ((𝐴𝐵𝐵𝐴) ↔ (𝐵𝐴𝐴𝐵))
42, 3bitri 263 . . . 4 (𝐴 = 𝐵 ↔ (𝐵𝐴𝐴𝐵))
54anbi1i 727 . . 3 ((𝐴 = 𝐵 ∧ ∀𝑥𝐴 (𝐹𝑥) = (𝐺𝑥)) ↔ ((𝐵𝐴𝐴𝐵) ∧ ∀𝑥𝐴 (𝐹𝑥) = (𝐺𝑥)))
6 anass 679 . . . 4 (((𝐵𝐴𝐴𝐵) ∧ ∀𝑥𝐴 (𝐹𝑥) = (𝐺𝑥)) ↔ (𝐵𝐴 ∧ (𝐴𝐵 ∧ ∀𝑥𝐴 (𝐹𝑥) = (𝐺𝑥))))
7 dfss3 3558 . . . . . . 7 (𝐴𝐵 ↔ ∀𝑥𝐴 𝑥𝐵)
87anbi1i 727 . . . . . 6 ((𝐴𝐵 ∧ ∀𝑥𝐴 (𝐹𝑥) = (𝐺𝑥)) ↔ (∀𝑥𝐴 𝑥𝐵 ∧ ∀𝑥𝐴 (𝐹𝑥) = (𝐺𝑥)))
9 r19.26 3046 . . . . . 6 (∀𝑥𝐴 (𝑥𝐵 ∧ (𝐹𝑥) = (𝐺𝑥)) ↔ (∀𝑥𝐴 𝑥𝐵 ∧ ∀𝑥𝐴 (𝐹𝑥) = (𝐺𝑥)))
108, 9bitr4i 266 . . . . 5 ((𝐴𝐵 ∧ ∀𝑥𝐴 (𝐹𝑥) = (𝐺𝑥)) ↔ ∀𝑥𝐴 (𝑥𝐵 ∧ (𝐹𝑥) = (𝐺𝑥)))
1110anbi2i 726 . . . 4 ((𝐵𝐴 ∧ (𝐴𝐵 ∧ ∀𝑥𝐴 (𝐹𝑥) = (𝐺𝑥))) ↔ (𝐵𝐴 ∧ ∀𝑥𝐴 (𝑥𝐵 ∧ (𝐹𝑥) = (𝐺𝑥))))
126, 11bitri 263 . . 3 (((𝐵𝐴𝐴𝐵) ∧ ∀𝑥𝐴 (𝐹𝑥) = (𝐺𝑥)) ↔ (𝐵𝐴 ∧ ∀𝑥𝐴 (𝑥𝐵 ∧ (𝐹𝑥) = (𝐺𝑥))))
135, 12bitri 263 . 2 ((𝐴 = 𝐵 ∧ ∀𝑥𝐴 (𝐹𝑥) = (𝐺𝑥)) ↔ (𝐵𝐴 ∧ ∀𝑥𝐴 (𝑥𝐵 ∧ (𝐹𝑥) = (𝐺𝑥))))
141, 13syl6bb 275 1 ((𝐹 Fn 𝐴𝐺 Fn 𝐵) → (𝐹 = 𝐺 ↔ (𝐵𝐴 ∧ ∀𝑥𝐴 (𝑥𝐵 ∧ (𝐹𝑥) = (𝐺𝑥)))))
Colors of variables: wff setvar class
Syntax hints:  wi 4  wb 195  wa 383   = wceq 1475  wcel 1977  wral 2896  wss 3540   Fn wfn 5799  cfv 5804
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1713  ax-4 1728  ax-5 1827  ax-6 1875  ax-7 1922  ax-8 1979  ax-9 1986  ax-10 2006  ax-11 2021  ax-12 2034  ax-13 2234  ax-ext 2590  ax-sep 4709  ax-nul 4717  ax-pow 4769  ax-pr 4833
This theorem depends on definitions:  df-bi 196  df-or 384  df-an 385  df-3an 1033  df-tru 1478  df-ex 1696  df-nf 1701  df-sb 1868  df-eu 2462  df-mo 2463  df-clab 2597  df-cleq 2603  df-clel 2606  df-nfc 2740  df-ral 2901  df-rex 2902  df-rab 2905  df-v 3175  df-sbc 3403  df-csb 3500  df-dif 3543  df-un 3545  df-in 3547  df-ss 3554  df-nul 3875  df-if 4037  df-sn 4126  df-pr 4128  df-op 4132  df-uni 4373  df-br 4584  df-opab 4644  df-mpt 4645  df-id 4953  df-xp 5044  df-rel 5045  df-cnv 5046  df-co 5047  df-dm 5048  df-rn 5049  df-res 5050  df-ima 5051  df-iota 5768  df-fun 5806  df-fn 5807  df-fv 5812
This theorem is referenced by: (None)
  Copyright terms: Public domain W3C validator