NFE Home New Foundations Explorer < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  NFE Home  >  Th. List  >  isoeq2 GIF version

Theorem isoeq2 5484
Description: Equality theorem for isomorphisms. (Contributed by set.mm contributors, 17-May-2004.)
Assertion
Ref Expression
isoeq2 (R = T → (H Isom R, S (A, B) ↔ H Isom T, S (A, B)))

Proof of Theorem isoeq2
Dummy variables x y are mutually distinct and distinct from all other variables.
StepHypRef Expression
1 breq 4642 . . . . 5 (R = T → (xRyxTy))
21bibi1d 310 . . . 4 (R = T → ((xRy ↔ (Hx)S(Hy)) ↔ (xTy ↔ (Hx)S(Hy))))
322ralbidv 2657 . . 3 (R = T → (x A y A (xRy ↔ (Hx)S(Hy)) ↔ x A y A (xTy ↔ (Hx)S(Hy))))
43anbi2d 684 . 2 (R = T → ((H:A1-1-ontoB x A y A (xRy ↔ (Hx)S(Hy))) ↔ (H:A1-1-ontoB x A y A (xTy ↔ (Hx)S(Hy)))))
5 df-iso 4797 . 2 (H Isom R, S (A, B) ↔ (H:A1-1-ontoB x A y A (xRy ↔ (Hx)S(Hy))))
6 df-iso 4797 . 2 (H Isom T, S (A, B) ↔ (H:A1-1-ontoB x A y A (xTy ↔ (Hx)S(Hy))))
74, 5, 63bitr4g 279 1 (R = T → (H Isom R, S (A, B) ↔ H Isom T, S (A, B)))
Colors of variables: wff setvar class
Syntax hints:  wi 4  wb 176   wa 358   = wceq 1642  wral 2615   class class class wbr 4640  1-1-ontowf1o 4781  cfv 4782   Isom wiso 4783
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1546  ax-5 1557  ax-17 1616  ax-9 1654  ax-8 1675  ax-11 1746  ax-ext 2334
This theorem depends on definitions:  df-bi 177  df-an 360  df-ex 1542  df-nf 1545  df-cleq 2346  df-clel 2349  df-ral 2620  df-br 4641  df-iso 4797
This theorem is referenced by: (None)
  Copyright terms: Public domain W3C validator