Theorem cbvditgdavw 36425

Description: Change bound variable in a directed integral. Deduction form. (Contributed by GG, 14-Aug-2025.)

Hypothesis

Ref	Expression
cbvditgdavw.1	⊢ ((𝜑 ∧ 𝑥 = 𝑦) → 𝐶 = 𝐷)

Assertion

Ref	Expression
cbvditgdavw	⊢ (𝜑 → ⨜[𝐴 → 𝐵]𝐶 d𝑥 = ⨜[𝐴 → 𝐵]𝐷 d𝑦)

Distinct variable groups:   𝜑,𝑥,𝑦   𝑥,𝐴,𝑦   𝑥,𝐵,𝑦   𝑦,𝐶   𝑥,𝐷

Allowed substitution hints:   𝐶(𝑥)   𝐷(𝑦)

Proof of Theorem cbvditgdavw

Step	Hyp	Ref	Expression
1		cbvditgdavw.1	. . . 4 ⊢ ((𝜑 ∧ 𝑥 = 𝑦) → 𝐶 = 𝐷)
2	1	cbvitgdavw 36424	. . 3 ⊢ (𝜑 → ∫(𝐴(,)𝐵)𝐶 d𝑥 = ∫(𝐴(,)𝐵)𝐷 d𝑦)
3	1	cbvitgdavw 36424	. . . 4 ⊢ (𝜑 → ∫(𝐵(,)𝐴)𝐶 d𝑥 = ∫(𝐵(,)𝐴)𝐷 d𝑦)
4	3	negeqd 11372	. . 3 ⊢ (𝜑 → -∫(𝐵(,)𝐴)𝐶 d𝑥 = -∫(𝐵(,)𝐴)𝐷 d𝑦)
5	2, 4	ifeq12d 4499	. 2 ⊢ (𝜑 → if(𝐴 ≤ 𝐵, ∫(𝐴(,)𝐵)𝐶 d𝑥, -∫(𝐵(,)𝐴)𝐶 d𝑥) = if(𝐴 ≤ 𝐵, ∫(𝐴(,)𝐵)𝐷 d𝑦, -∫(𝐵(,)𝐴)𝐷 d𝑦))
6		df-ditg 25802	. 2 ⊢ ⨜[𝐴 → 𝐵]𝐶 d𝑥 = if(𝐴 ≤ 𝐵, ∫(𝐴(,)𝐵)𝐶 d𝑥, -∫(𝐵(,)𝐴)𝐶 d𝑥)
7		df-ditg 25802	. 2 ⊢ ⨜[𝐴 → 𝐵]𝐷 d𝑦 = if(𝐴 ≤ 𝐵, ∫(𝐴(,)𝐵)𝐷 d𝑦, -∫(𝐵(,)𝐴)𝐷 d𝑦)
8	5, 6, 7	3eqtr4g 2794	1 ⊢ (𝜑 → ⨜[𝐴 → 𝐵]𝐶 d𝑥 = ⨜[𝐴 → 𝐵]𝐷 d𝑦)

Syntax hints:   → wi 4   ∧ wa 395   = wceq 1541  ifcif 4477   class class class wbr 5096  (class class class)co 7356   ≤ cle 11165  -cneg 11363  (,)cioo 13259  ∫citg 25573  ⨜cdit 25801

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1796  ax-4 1810  ax-5 1911  ax-6 1968  ax-7 2009  ax-8 2115  ax-9 2123  ax-ext 2706

This theorem depends on definitions:  df-bi 207  df-an 396  df-or 848  df-3an 1088  df-tru 1544  df-fal 1554  df-ex 1781  df-sb 2068  df-clab 2713  df-cleq 2726  df-clel 2809  df-ral 3050  df-rex 3059  df-rab 3398  df-v 3440  df-sbc 3739  df-csb 3848  df-dif 3902  df-un 3904  df-in 3906  df-ss 3916  df-nul 4284  df-if 4478  df-sn 4579  df-pr 4581  df-op 4585  df-uni 4862  df-br 5097  df-opab 5159  df-mpt 5178  df-xp 5628  df-cnv 5630  df-co 5631  df-dm 5632  df-rn 5633  df-res 5634  df-ima 5635  df-pred 6257  df-iota 6446  df-fv 6498  df-ov 7359  df-oprab 7360  df-mpo 7361  df-frecs 8221  df-wrecs 8252  df-recs 8301  df-rdg 8339  df-neg 11365  df-seq 13923  df-sum 15608  df-itg 25578  df-ditg 25802

This theorem is referenced by: (None)