Theorem gsummpt2co 33136

Description: Split a finite sum into a sum of a collection of sums over disjoint subsets. (Contributed by Thierry Arnoux, 27-Mar-2018.)

Hypotheses

Ref	Expression
gsummpt2co.b	⊢ 𝐵 = (Base‘𝑊)
gsummpt2co.z	⊢ 0 = (0g‘𝑊)
gsummpt2co.w	⊢ (𝜑 → 𝑊 ∈ CMnd)
gsummpt2co.a	⊢ (𝜑 → 𝐴 ∈ Fin)
gsummpt2co.e	⊢ (𝜑 → 𝐸 ∈ 𝑉)
gsummpt2co.1	⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 𝐶 ∈ 𝐵)
gsummpt2co.2	⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 𝐷 ∈ 𝐸)
gsummpt2co.3	⊢ 𝐹 = (𝑥 ∈ 𝐴 ↦ 𝐷)

Assertion

Ref	Expression
gsummpt2co	⊢ (𝜑 → (𝑊 Σg (𝑥 ∈ 𝐴 ↦ 𝐶)) = (𝑊 Σg (𝑦 ∈ 𝐸 ↦ (𝑊 Σg (𝑥 ∈ (◡𝐹 “ {𝑦}) ↦ 𝐶)))))

Distinct variable groups:   𝑥, 0 ,𝑦   𝑥,𝐴,𝑦   𝑥,𝐵,𝑦   𝑦,𝐶   𝑥,𝐸,𝑦   𝑥,𝐹,𝑦   𝑦,𝑉   𝑥,𝑊,𝑦   𝜑,𝑥

Allowed substitution hints:   𝜑(𝑦)   𝐶(𝑥)   𝐷(𝑥,𝑦)   𝑉(𝑥)

Proof of Theorem gsummpt2co

Dummy variables 𝑧 𝑝 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		nfcsb1v 3862	. . . 4 ⊢ Ⅎ𝑥⦋(2nd ‘𝑝) / 𝑥⦌𝐶
2		gsummpt2co.b	. . . 4 ⊢ 𝐵 = (Base‘𝑊)
3		gsummpt2co.z	. . . 4 ⊢ 0 = (0g‘𝑊)
4		csbeq1a 3852	. . . 4 ⊢ (𝑥 = (2nd ‘𝑝) → 𝐶 = ⦋(2nd ‘𝑝) / 𝑥⦌𝐶)
5		gsummpt2co.w	. . . 4 ⊢ (𝜑 → 𝑊 ∈ CMnd)
6		gsummpt2co.a	. . . 4 ⊢ (𝜑 → 𝐴 ∈ Fin)
7		ssidd 3945	. . . 4 ⊢ (𝜑 → 𝐵 ⊆ 𝐵)
8		gsummpt2co.1	. . . 4 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 𝐶 ∈ 𝐵)
9		elcnv 5825	. . . . . 6 ⊢ (𝑝 ∈ ◡𝐹 ↔ ∃𝑧∃𝑥(𝑝 = ⟨𝑧, 𝑥⟩ ∧ 𝑥𝐹𝑧))
10		vex 3436	. . . . . . . . . 10 ⊢ 𝑧 ∈ V
11		vex 3436	. . . . . . . . . 10 ⊢ 𝑥 ∈ V
12	10, 11	op2ndd 7949	. . . . . . . . 9 ⊢ (𝑝 = ⟨𝑧, 𝑥⟩ → (2nd ‘𝑝) = 𝑥)
13	12	adantr 481	. . . . . . . 8 ⊢ ((𝑝 = ⟨𝑧, 𝑥⟩ ∧ 𝑥𝐹𝑧) → (2nd ‘𝑝) = 𝑥)
14		gsummpt2co.3	. . . . . . . . . . 11 ⊢ 𝐹 = (𝑥 ∈ 𝐴 ↦ 𝐷)
15	14	dmmptss 6199	. . . . . . . . . 10 ⊢ dom 𝐹 ⊆ 𝐴
16	11, 10	breldm 5857	. . . . . . . . . 10 ⊢ (𝑥𝐹𝑧 → 𝑥 ∈ dom 𝐹)
17	15, 16	sselid 3920	. . . . . . . . 9 ⊢ (𝑥𝐹𝑧 → 𝑥 ∈ 𝐴)
18	17	adantl 482	. . . . . . . 8 ⊢ ((𝑝 = ⟨𝑧, 𝑥⟩ ∧ 𝑥𝐹𝑧) → 𝑥 ∈ 𝐴)
19	13, 18	eqeltrd 2840	. . . . . . 7 ⊢ ((𝑝 = ⟨𝑧, 𝑥⟩ ∧ 𝑥𝐹𝑧) → (2nd ‘𝑝) ∈ 𝐴)
20	19	exlimivv 1939	. . . . . 6 ⊢ (∃𝑧∃𝑥(𝑝 = ⟨𝑧, 𝑥⟩ ∧ 𝑥𝐹𝑧) → (2nd ‘𝑝) ∈ 𝐴)
21	9, 20	sylbi 218	. . . . 5 ⊢ (𝑝 ∈ ◡𝐹 → (2nd ‘𝑝) ∈ 𝐴)
22	21	adantl 482	. . . 4 ⊢ ((𝜑 ∧ 𝑝 ∈ ◡𝐹) → (2nd ‘𝑝) ∈ 𝐴)
23	14	funmpt2 6531	. . . . . . 7 ⊢ Fun 𝐹
24		funcnvcnv 6559	. . . . . . 7 ⊢ (Fun 𝐹 → Fun ◡◡𝐹)
25	23, 24	ax-mp 5	. . . . . 6 ⊢ Fun ◡◡𝐹
26	25	a1i 11	. . . . 5 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → Fun ◡◡𝐹)
27		dfdm4 5844	. . . . . . . 8 ⊢ dom 𝐹 = ran ◡𝐹
28	14	dmeqi 5853	. . . . . . . . 9 ⊢ dom 𝐹 = dom (𝑥 ∈ 𝐴 ↦ 𝐷)
29		gsummpt2co.2	. . . . . . . . . . 11 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 𝐷 ∈ 𝐸)
30	29	ralrimiva 3132	. . . . . . . . . 10 ⊢ (𝜑 → ∀𝑥 ∈ 𝐴 𝐷 ∈ 𝐸)
31		dmmptg 6200	. . . . . . . . . 10 ⊢ (∀𝑥 ∈ 𝐴 𝐷 ∈ 𝐸 → dom (𝑥 ∈ 𝐴 ↦ 𝐷) = 𝐴)
32	30, 31	syl 17	. . . . . . . . 9 ⊢ (𝜑 → dom (𝑥 ∈ 𝐴 ↦ 𝐷) = 𝐴)
33	28, 32	eqtrid 2787	. . . . . . . 8 ⊢ (𝜑 → dom 𝐹 = 𝐴)
34	27, 33	eqtr3id 2789	. . . . . . 7 ⊢ (𝜑 → ran ◡𝐹 = 𝐴)
35	34	eleq2d 2826	. . . . . 6 ⊢ (𝜑 → (𝑥 ∈ ran ◡𝐹 ↔ 𝑥 ∈ 𝐴))
36	35	biimpar 478	. . . . 5 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 𝑥 ∈ ran ◡𝐹)
37		relcnv 6063	. . . . . 6 ⊢ Rel ◡𝐹
38		fcnvgreu 32771	. . . . . 6 ⊢ (((Rel ◡𝐹 ∧ Fun ◡◡𝐹) ∧ 𝑥 ∈ ran ◡𝐹) → ∃!𝑝 ∈ ◡ 𝐹𝑥 = (2nd ‘𝑝))
39	37, 38	mpanl1 706	. . . . 5 ⊢ ((Fun ◡◡𝐹 ∧ 𝑥 ∈ ran ◡𝐹) → ∃!𝑝 ∈ ◡ 𝐹𝑥 = (2nd ‘𝑝))
40	26, 36, 39	syl2anc 590	. . . 4 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → ∃!𝑝 ∈ ◡ 𝐹𝑥 = (2nd ‘𝑝))
41	1, 2, 3, 4, 5, 6, 7, 8, 22, 40	gsummptf1o 19936	. . 3 ⊢ (𝜑 → (𝑊 Σg (𝑥 ∈ 𝐴 ↦ 𝐶)) = (𝑊 Σg (𝑝 ∈ ◡𝐹 ↦ ⦋(2nd ‘𝑝) / 𝑥⦌𝐶)))
42	14	rnmptss 7071	. . . . . . . 8 ⊢ (∀𝑥 ∈ 𝐴 𝐷 ∈ 𝐸 → ran 𝐹 ⊆ 𝐸)
43	30, 42	syl 17	. . . . . . 7 ⊢ (𝜑 → ran 𝐹 ⊆ 𝐸)
44		dfcnv2 32774	. . . . . . 7 ⊢ (ran 𝐹 ⊆ 𝐸 → ◡𝐹 = ∪ 𝑧 ∈ 𝐸 ({𝑧} × (◡𝐹 “ {𝑧})))
45	43, 44	syl 17	. . . . . 6 ⊢ (𝜑 → ◡𝐹 = ∪ 𝑧 ∈ 𝐸 ({𝑧} × (◡𝐹 “ {𝑧})))
46	45	mpteq1d 5169	. . . . 5 ⊢ (𝜑 → (𝑝 ∈ ◡𝐹 ↦ ⦋(2nd ‘𝑝) / 𝑥⦌𝐶) = (𝑝 ∈ ∪ 𝑧 ∈ 𝐸 ({𝑧} × (◡𝐹 “ {𝑧})) ↦ ⦋(2nd ‘𝑝) / 𝑥⦌𝐶))
47		nfcv 2902	. . . . . 6 ⊢ Ⅎ𝑧⦋(2nd ‘𝑝) / 𝑥⦌𝐶
48		csbeq1 3841	. . . . . . . 8 ⊢ ((2nd ‘𝑝) = 𝑥 → ⦋(2nd ‘𝑝) / 𝑥⦌𝐶 = ⦋𝑥 / 𝑥⦌𝐶)
49	12, 48	syl 17	. . . . . . 7 ⊢ (𝑝 = ⟨𝑧, 𝑥⟩ → ⦋(2nd ‘𝑝) / 𝑥⦌𝐶 = ⦋𝑥 / 𝑥⦌𝐶)
50		csbid 3851	. . . . . . 7 ⊢ ⦋𝑥 / 𝑥⦌𝐶 = 𝐶
51	49, 50	eqtrdi 2791	. . . . . 6 ⊢ (𝑝 = ⟨𝑧, 𝑥⟩ → ⦋(2nd ‘𝑝) / 𝑥⦌𝐶 = 𝐶)
52	47, 1, 51	mpomptxf 32777	. . . . 5 ⊢ (𝑝 ∈ ∪ 𝑧 ∈ 𝐸 ({𝑧} × (◡𝐹 “ {𝑧})) ↦ ⦋(2nd ‘𝑝) / 𝑥⦌𝐶) = (𝑧 ∈ 𝐸, 𝑥 ∈ (◡𝐹 “ {𝑧}) ↦ 𝐶)
53	46, 52	eqtrdi 2791	. . . 4 ⊢ (𝜑 → (𝑝 ∈ ◡𝐹 ↦ ⦋(2nd ‘𝑝) / 𝑥⦌𝐶) = (𝑧 ∈ 𝐸, 𝑥 ∈ (◡𝐹 “ {𝑧}) ↦ 𝐶))
54	53	oveq2d 7379	. . 3 ⊢ (𝜑 → (𝑊 Σg (𝑝 ∈ ◡𝐹 ↦ ⦋(2nd ‘𝑝) / 𝑥⦌𝐶)) = (𝑊 Σg (𝑧 ∈ 𝐸, 𝑥 ∈ (◡𝐹 “ {𝑧}) ↦ 𝐶)))
55		gsummpt2co.e	. . . 4 ⊢ (𝜑 → 𝐸 ∈ 𝑉)
56		mptfi 9258	. . . . . . . 8 ⊢ (𝐴 ∈ Fin → (𝑥 ∈ 𝐴 ↦ 𝐷) ∈ Fin)
57	14, 56	eqeltrid 2844	. . . . . . 7 ⊢ (𝐴 ∈ Fin → 𝐹 ∈ Fin)
58		cnvfi 9107	. . . . . . 7 ⊢ (𝐹 ∈ Fin → ◡𝐹 ∈ Fin)
59	6, 57, 58	3syl 18	. . . . . 6 ⊢ (𝜑 → ◡𝐹 ∈ Fin)
60		imaexg 7860	. . . . . 6 ⊢ (◡𝐹 ∈ Fin → (◡𝐹 “ {𝑧}) ∈ V)
61	59, 60	syl 17	. . . . 5 ⊢ (𝜑 → (◡𝐹 “ {𝑧}) ∈ V)
62	61	adantr 481	. . . 4 ⊢ ((𝜑 ∧ 𝑧 ∈ 𝐸) → (◡𝐹 “ {𝑧}) ∈ V)
63		simpll 772	. . . . . 6 ⊢ (((𝜑 ∧ 𝑧 ∈ 𝐸) ∧ 𝑥 ∈ (◡𝐹 “ {𝑧})) → 𝜑)
64		imassrn 6030	. . . . . . . . 9 ⊢ (◡𝐹 “ {𝑧}) ⊆ ran ◡𝐹
65	64, 27	sseqtrri 3971	. . . . . . . 8 ⊢ (◡𝐹 “ {𝑧}) ⊆ dom 𝐹
66	65, 15	sstri 3931	. . . . . . 7 ⊢ (◡𝐹 “ {𝑧}) ⊆ 𝐴
67	10, 11	elimasn 6049	. . . . . . . . 9 ⊢ (𝑥 ∈ (◡𝐹 “ {𝑧}) ↔ ⟨𝑧, 𝑥⟩ ∈ ◡𝐹)
68	67	bilani 505	. . . . . . . 8 ⊢ (((𝜑 ∧ 𝑧 ∈ 𝐸) ∧ 𝑥 ∈ (◡𝐹 “ {𝑧})) → ⟨𝑧, 𝑥⟩ ∈ ◡𝐹)
69	68, 67	sylibr 235	. . . . . . 7 ⊢ (((𝜑 ∧ 𝑧 ∈ 𝐸) ∧ 𝑥 ∈ (◡𝐹 “ {𝑧})) → 𝑥 ∈ (◡𝐹 “ {𝑧}))
70	66, 69	sselid 3920	. . . . . 6 ⊢ (((𝜑 ∧ 𝑧 ∈ 𝐸) ∧ 𝑥 ∈ (◡𝐹 “ {𝑧})) → 𝑥 ∈ 𝐴)
71	63, 70, 8	syl2anc 590	. . . . 5 ⊢ (((𝜑 ∧ 𝑧 ∈ 𝐸) ∧ 𝑥 ∈ (◡𝐹 “ {𝑧})) → 𝐶 ∈ 𝐵)
72	71	anasss 467	. . . 4 ⊢ ((𝜑 ∧ (𝑧 ∈ 𝐸 ∧ 𝑥 ∈ (◡𝐹 “ {𝑧}))) → 𝐶 ∈ 𝐵)
73		df-br 5080	. . . . . . . . 9 ⊢ (𝑧◡𝐹𝑥 ↔ ⟨𝑧, 𝑥⟩ ∈ ◡𝐹)
74	68, 73	sylibr 235	. . . . . . . 8 ⊢ (((𝜑 ∧ 𝑧 ∈ 𝐸) ∧ 𝑥 ∈ (◡𝐹 “ {𝑧})) → 𝑧◡𝐹𝑥)
75	74	anasss 467	. . . . . . 7 ⊢ ((𝜑 ∧ (𝑧 ∈ 𝐸 ∧ 𝑥 ∈ (◡𝐹 “ {𝑧}))) → 𝑧◡𝐹𝑥)
76	75	pm2.24d 151	. . . . . 6 ⊢ ((𝜑 ∧ (𝑧 ∈ 𝐸 ∧ 𝑥 ∈ (◡𝐹 “ {𝑧}))) → (¬ 𝑧◡𝐹𝑥 → 𝐶 = 0 ))
77	76	imp 407	. . . . 5 ⊢ (((𝜑 ∧ (𝑧 ∈ 𝐸 ∧ 𝑥 ∈ (◡𝐹 “ {𝑧}))) ∧ ¬ 𝑧◡𝐹𝑥) → 𝐶 = 0 )
78	77	anasss 467	. . . 4 ⊢ ((𝜑 ∧ ((𝑧 ∈ 𝐸 ∧ 𝑥 ∈ (◡𝐹 “ {𝑧})) ∧ ¬ 𝑧◡𝐹𝑥)) → 𝐶 = 0 )
79	2, 3, 5, 55, 62, 72, 59, 78	gsum2d2 19947	. . 3 ⊢ (𝜑 → (𝑊 Σg (𝑧 ∈ 𝐸, 𝑥 ∈ (◡𝐹 “ {𝑧}) ↦ 𝐶)) = (𝑊 Σg (𝑧 ∈ 𝐸 ↦ (𝑊 Σg (𝑥 ∈ (◡𝐹 “ {𝑧}) ↦ 𝐶)))))
80	41, 54, 79	3eqtrd 2779	. 2 ⊢ (𝜑 → (𝑊 Σg (𝑥 ∈ 𝐴 ↦ 𝐶)) = (𝑊 Σg (𝑧 ∈ 𝐸 ↦ (𝑊 Σg (𝑥 ∈ (◡𝐹 “ {𝑧}) ↦ 𝐶)))))
81		nfcv 2902	. . . 4 ⊢ Ⅎ𝑧(𝑊 Σg (𝑥 ∈ (◡𝐹 “ {𝑦}) ↦ 𝐶))
82		nfcv 2902	. . . 4 ⊢ Ⅎ𝑦(𝑊 Σg (𝑥 ∈ (◡𝐹 “ {𝑧}) ↦ 𝐶))
83		sneq 4572	. . . . . . 7 ⊢ (𝑦 = 𝑧 → {𝑦} = {𝑧})
84	83	imaeq2d 6019	. . . . . 6 ⊢ (𝑦 = 𝑧 → (◡𝐹 “ {𝑦}) = (◡𝐹 “ {𝑧}))
85	84	mpteq1d 5169	. . . . 5 ⊢ (𝑦 = 𝑧 → (𝑥 ∈ (◡𝐹 “ {𝑦}) ↦ 𝐶) = (𝑥 ∈ (◡𝐹 “ {𝑧}) ↦ 𝐶))
86	85	oveq2d 7379	. . . 4 ⊢ (𝑦 = 𝑧 → (𝑊 Σg (𝑥 ∈ (◡𝐹 “ {𝑦}) ↦ 𝐶)) = (𝑊 Σg (𝑥 ∈ (◡𝐹 “ {𝑧}) ↦ 𝐶)))
87	81, 82, 86	cbvmpt 5181	. . 3 ⊢ (𝑦 ∈ 𝐸 ↦ (𝑊 Σg (𝑥 ∈ (◡𝐹 “ {𝑦}) ↦ 𝐶))) = (𝑧 ∈ 𝐸 ↦ (𝑊 Σg (𝑥 ∈ (◡𝐹 “ {𝑧}) ↦ 𝐶)))
88	87	oveq2i 7374	. 2 ⊢ (𝑊 Σg (𝑦 ∈ 𝐸 ↦ (𝑊 Σg (𝑥 ∈ (◡𝐹 “ {𝑦}) ↦ 𝐶)))) = (𝑊 Σg (𝑧 ∈ 𝐸 ↦ (𝑊 Σg (𝑥 ∈ (◡𝐹 “ {𝑧}) ↦ 𝐶))))
89	80, 88	eqtr4di 2793	1 ⊢ (𝜑 → (𝑊 Σg (𝑥 ∈ 𝐴 ↦ 𝐶)) = (𝑊 Σg (𝑦 ∈ 𝐸 ↦ (𝑊 Σg (𝑥 ∈ (◡𝐹 “ {𝑦}) ↦ 𝐶)))))

Syntax hints:  ¬ wn 3   → wi 4   ∧ wa 396   = wceq 1547  ∃wex 1786   ∈ wcel 2119  ∀wral 3054  ∃!wreu 3343  Vcvv 3432  ⦋csb 3838   ⊆ wss 3890  {csn 4562  ⟨cop 4568  ∪ ciun 4928   class class class wbr 5079   ↦ cmpt 5160   × cxp 5623  ^◡ccnv 5624  dom cdm 5625  ran crn 5626   “ cima 5628  Rel wrel 5630  Fun wfun 6486  ‘cfv 6492  (class class class)co 7363   ∈ cmpo 7365  2^nd c2nd 7937  Fincfn 8890  Basecbs 17177  0_gc0g 17400   Σ_g cgsu 17401  CMndccmn 19753

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1802  ax-4 1816  ax-5 1917  ax-6 1974  ax-7 2015  ax-8 2121  ax-9 2129  ax-10 2152  ax-11 2168  ax-12 2189  ax-ext 2712  ax-rep 5206  ax-sep 5225  ax-nul 5235  ax-pow 5301  ax-pr 5369  ax-un 7685  ax-cnex 11092  ax-resscn 11093  ax-1cn 11094  ax-icn 11095  ax-addcl 11096  ax-addrcl 11097  ax-mulcl 11098  ax-mulrcl 11099  ax-mulcom 11100  ax-addass 11101  ax-mulass 11102  ax-distr 11103  ax-i2m1 11104  ax-1ne0 11105  ax-1rid 11106  ax-rnegex 11107  ax-rrecex 11108  ax-cnre 11109  ax-pre-lttri 11110  ax-pre-lttrn 11111  ax-pre-ltadd 11112  ax-pre-mulgt0 11113

This theorem depends on definitions:  df-bi 208  df-an 397  df-or 854  df-3or 1093  df-3an 1094  df-tru 1550  df-fal 1560  df-ex 1787  df-nf 1791  df-sb 2074  df-mo 2543  df-eu 2573  df-clab 2719  df-cleq 2732  df-clel 2815  df-nfc 2889  df-ne 2936  df-nel 3040  df-ral 3055  df-rex 3065  df-rmo 3345  df-reu 3346  df-rab 3393  df-v 3434  df-sbc 3731  df-csb 3839  df-dif 3893  df-un 3895  df-in 3897  df-ss 3907  df-pss 3910  df-nul 4269  df-if 4462  df-pw 4538  df-sn 4563  df-pr 4565  df-op 4569  df-uni 4846  df-int 4885  df-iun 4930  df-iin 4931  df-br 5080  df-opab 5142  df-mpt 5161  df-tr 5187  df-id 5520  df-eprel 5525  df-po 5533  df-so 5534  df-fr 5578  df-se 5579  df-we 5580  df-xp 5631  df-rel 5632  df-cnv 5633  df-co 5634  df-dm 5635  df-rn 5636  df-res 5637  df-ima 5638  df-pred 6259  df-ord 6320  df-on 6321  df-lim 6322  df-suc 6323  df-iota 6448  df-fun 6494  df-fn 6495  df-f 6496  df-f1 6497  df-fo 6498  df-f1o 6499  df-fv 6500  df-isom 6501  df-riota 7320  df-ov 7366  df-oprab 7367  df-mpo 7368  df-of 7627  df-om 7814  df-1st 7938  df-2nd 7939  df-supp 8108  df-frecs 8228  df-wrecs 8259  df-recs 8308  df-rdg 8346  df-1o 8402  df-2o 8403  df-er 8640  df-en 8891  df-dom 8892  df-sdom 8893  df-fin 8894  df-fsupp 9272  df-oi 9422  df-card 9861  df-pnf 11179  df-mnf 11180  df-xr 11181  df-ltxr 11182  df-le 11183  df-sub 11377  df-neg 11378  df-nn 12173  df-2 12242  df-n0 12436  df-z 12523  df-uz 12787  df-fz 13460  df-fzo 13607  df-seq 13962  df-hash 14291  df-sets 17132  df-slot 17150  df-ndx 17162  df-base 17178  df-ress 17199  df-plusg 17231  df-0g 17402  df-gsum 17403  df-mre 17546  df-mrc 17547  df-acs 17549  df-mgm 18606  df-sgrp 18685  df-mnd 18701  df-submnd 18750  df-mulg 19042  df-cntz 19290  df-cmn 19755

This theorem is referenced by:  gsummpt2d  33137  elrgspnsubrunlem2  33336