Theorem mnd32g 17128

Description: Commutative/associative law for monoids, with an explicit commutativity hypothesis. (Contributed by Mario Carneiro, 21-Apr-2016.)

Hypotheses

Ref	Expression
mndcl.b	⊢ 𝐵 = (Base‘𝐺)
mndcl.p	⊢ + = (+g‘𝐺)
mnd4g.1	⊢ (𝜑 → 𝐺 ∈ Mnd)
mnd4g.2	⊢ (𝜑 → 𝑋 ∈ 𝐵)
mnd4g.3	⊢ (𝜑 → 𝑌 ∈ 𝐵)
mnd4g.4	⊢ (𝜑 → 𝑍 ∈ 𝐵)
mnd32g.5	⊢ (𝜑 → (𝑌 + 𝑍) = (𝑍 + 𝑌))

Assertion

Ref	Expression
mnd32g	⊢ (𝜑 → ((𝑋 + 𝑌) + 𝑍) = ((𝑋 + 𝑍) + 𝑌))

Proof of Theorem mnd32g

Step	Hyp	Ref	Expression
1		mnd32g.5	. . 3 ⊢ (𝜑 → (𝑌 + 𝑍) = (𝑍 + 𝑌))
2	1	oveq2d 6565	. 2 ⊢ (𝜑 → (𝑋 + (𝑌 + 𝑍)) = (𝑋 + (𝑍 + 𝑌)))
3		mnd4g.1	. . 3 ⊢ (𝜑 → 𝐺 ∈ Mnd)
4		mnd4g.2	. . 3 ⊢ (𝜑 → 𝑋 ∈ 𝐵)
5		mnd4g.3	. . 3 ⊢ (𝜑 → 𝑌 ∈ 𝐵)
6		mnd4g.4	. . 3 ⊢ (𝜑 → 𝑍 ∈ 𝐵)
7		mndcl.b	. . . 4 ⊢ 𝐵 = (Base‘𝐺)
8		mndcl.p	. . . 4 ⊢ + = (+g‘𝐺)
9	7, 8	mndass 17125	. . 3 ⊢ ((𝐺 ∈ Mnd ∧ (𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵 ∧ 𝑍 ∈ 𝐵)) → ((𝑋 + 𝑌) + 𝑍) = (𝑋 + (𝑌 + 𝑍)))
10	3, 4, 5, 6, 9	syl13anc 1320	. 2 ⊢ (𝜑 → ((𝑋 + 𝑌) + 𝑍) = (𝑋 + (𝑌 + 𝑍)))
11	7, 8	mndass 17125	. . 3 ⊢ ((𝐺 ∈ Mnd ∧ (𝑋 ∈ 𝐵 ∧ 𝑍 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵)) → ((𝑋 + 𝑍) + 𝑌) = (𝑋 + (𝑍 + 𝑌)))
12	3, 4, 6, 5, 11	syl13anc 1320	. 2 ⊢ (𝜑 → ((𝑋 + 𝑍) + 𝑌) = (𝑋 + (𝑍 + 𝑌)))
13	2, 10, 12	3eqtr4d 2654	1 ⊢ (𝜑 → ((𝑋 + 𝑌) + 𝑍) = ((𝑋 + 𝑍) + 𝑌))

Syntax hints:   → wi 4   = wceq 1475   ∈ wcel 1977  ‘cfv 5804  (class class class)co 6549  Basecbs 15695  +_gcplusg 15768  Mndcmnd 17117

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1713  ax-4 1728  ax-5 1827  ax-6 1875  ax-7 1922  ax-10 2006  ax-11 2021  ax-12 2034  ax-13 2234  ax-ext 2590  ax-nul 4717

This theorem depends on definitions:  df-bi 196  df-or 384  df-an 385  df-3an 1033  df-tru 1478  df-ex 1696  df-nf 1701  df-sb 1868  df-eu 2462  df-clab 2597  df-cleq 2603  df-clel 2606  df-nfc 2740  df-ral 2901  df-rex 2902  df-rab 2905  df-v 3175  df-sbc 3403  df-dif 3543  df-un 3545  df-in 3547  df-ss 3554  df-nul 3875  df-if 4037  df-sn 4126  df-pr 4128  df-op 4132  df-uni 4373  df-br 4584  df-iota 5768  df-fv 5812  df-ov 6552  df-sgrp 17107  df-mnd 17118

This theorem is referenced by:  cmn32  18034