Theorem dcbid 782

Description: The equivalent of a decidable proposition is decidable. (Contributed by Jim Kingdon, 7-Sep-2019.)

Hypothesis

Ref	Expression
dcbid.1	⊢ (𝜑 → (𝜓 ↔ 𝜒))

Assertion

Ref	Expression
dcbid	⊢ (𝜑 → (DECID 𝜓 ↔ DECID 𝜒))

Proof of Theorem dcbid

Step	Hyp	Ref	Expression
1		dcbid.1	. . 3 ⊢ (𝜑 → (𝜓 ↔ 𝜒))
2	1	notbid 625	. . 3 ⊢ (𝜑 → (¬ 𝜓 ↔ ¬ 𝜒))
3	1, 2	orbi12d 740	. 2 ⊢ (𝜑 → ((𝜓 ∨ ¬ 𝜓) ↔ (𝜒 ∨ ¬ 𝜒)))
4		df-dc 777	. 2 ⊢ (DECID 𝜓 ↔ (𝜓 ∨ ¬ 𝜓))
5		df-dc 777	. 2 ⊢ (DECID 𝜒 ↔ (𝜒 ∨ ¬ 𝜒))
6	3, 4, 5	3bitr4g 221	1 ⊢ (𝜑 → (DECID 𝜓 ↔ DECID 𝜒))

Syntax hints:  ¬ wn 3   → wi 4   ↔ wb 103   ∨ wo 662  DECID wdc 776

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-in1 577  ax-in2 578  ax-io 663

This theorem depends on definitions:  df-bi 115  df-dc 777

This theorem is referenced by:  exmidexmid  3995  exmidel  3998  dcdifsnid  6195  finexdc  6545  undifdcss  6560  ssfirab  6568  ltdcpi  6785  enqdc  6823  enqdc1  6824  ltdcnq  6859  exfzdc  9540  sumeq1  10566  sumdc  10569  dvdsdc  10584  zdvdsdc  10597  zsupcllemstep  10721  infssuzex  10725  hashdvds  10977  sumdc2  11042