Theorem 3bitr3g 221

Description: More general version of 3bitr3i 209. Useful for converting definitions in a formula. (Contributed by NM, 4-Jun-1995.)

Hypotheses

Ref	Expression
3bitr3g.1	⊢ (𝜑 → (𝜓 ↔ 𝜒))
3bitr3g.2	⊢ (𝜓 ↔ 𝜃)
3bitr3g.3	⊢ (𝜒 ↔ 𝜏)

Assertion

Ref	Expression
3bitr3g	⊢ (𝜑 → (𝜃 ↔ 𝜏))

Proof of Theorem 3bitr3g

Step	Hyp	Ref	Expression
1		3bitr3g.2	. . 3 ⊢ (𝜓 ↔ 𝜃)
2		3bitr3g.1	. . 3 ⊢ (𝜑 → (𝜓 ↔ 𝜒))
3	1, 2	syl5bbr 193	. 2 ⊢ (𝜑 → (𝜃 ↔ 𝜒))
4		3bitr3g.3	. 2 ⊢ (𝜒 ↔ 𝜏)
5	3, 4	syl6bb 195	1 ⊢ (𝜑 → (𝜃 ↔ 𝜏))

Syntax hints:   → wi 4   ↔ wb 104

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107

This theorem depends on definitions:  df-bi 116

This theorem is referenced by:  con2bidc  860  sbal1yz  1976  sbal1  1977  dfsbcq2  2912  iindif2m  3880  opeqex  4171  rabxfrd  4390  eqbrrdv  4636  eqbrrdiv  4637  opelco2g  4707  opelcnvg  4719  ralrnmpt  5562  rexrnmpt  5563  fliftcnv  5696  eusvobj2  5760  f1od2  6132  ottposg  6152  ercnv  6450  exmidpw  6802  djuf1olem  6938  fzen  9823  fihasheq0  10540  divalgb  11622  isprm3  11799  eldvap  12820