Theorem add12d 8487

Description: Commutative/associative law that swaps the first two terms in a triple sum. (Contributed by Mario Carneiro, 27-May-2016.)

Hypotheses

Ref	Expression
addd.1	⊢ (𝜑 → 𝐴 ∈ ℂ)
addd.2	⊢ (𝜑 → 𝐵 ∈ ℂ)
addd.3	⊢ (𝜑 → 𝐶 ∈ ℂ)

Assertion

Ref	Expression
add12d	⊢ (𝜑 → (𝐴 + (𝐵 + 𝐶)) = (𝐵 + (𝐴 + 𝐶)))

Proof of Theorem add12d

Step	Hyp	Ref	Expression
1		addd.1	. 2 ⊢ (𝜑 → 𝐴 ∈ ℂ)
2		addd.2	. 2 ⊢ (𝜑 → 𝐵 ∈ ℂ)
3		addd.3	. 2 ⊢ (𝜑 → 𝐶 ∈ ℂ)
4		add12 8478	. 2 ⊢ ((𝐴 ∈ ℂ ∧ 𝐵 ∈ ℂ ∧ 𝐶 ∈ ℂ) → (𝐴 + (𝐵 + 𝐶)) = (𝐵 + (𝐴 + 𝐶)))
5	1, 2, 3, 4	syl3anc 1278	1 ⊢ (𝜑 → (𝐴 + (𝐵 + 𝐶)) = (𝐵 + (𝐴 + 𝐶)))

Syntax hints:   → wi 4   = wceq 1402   ∈ wcel 2209  (class class class)co 6079  ℂcc 8171   + caddc 8176

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-io 721  ax-5 1500  ax-7 1501  ax-gen 1502  ax-ie1 1546  ax-ie2 1547  ax-8 1557  ax-10 1558  ax-11 1559  ax-i12 1560  ax-bndl 1562  ax-4 1563  ax-17 1579  ax-i9 1583  ax-ial 1587  ax-i5r 1588  ax-ext 2220  ax-addcom 8273  ax-addass 8275

This theorem depends on definitions:  df-bi 117  df-3an 1011  df-tru 1405  df-nf 1514  df-sb 1816  df-clab 2225  df-cleq 2231  df-clel 2234  df-nfc 2381  df-rex 2534  df-v 2823  df-un 3224  df-sn 3714  df-pr 3715  df-op 3717  df-uni 3934  df-br 4129  df-iota 5335  df-fv 5383  df-ov 6082

This theorem is referenced by:  subsub2  8548  bdtrilem  11988  pcadd2  13103