Theorem cats1un 11192

Description: Express a word with an extra symbol as the union of the word and the new value. (Contributed by Mario Carneiro, 28-Feb-2016.)

Assertion

Ref	Expression
cats1un	⊢ ((𝐴 ∈ Word 𝑋 ∧ 𝐵 ∈ 𝑋) → (𝐴 ++ ⟨“𝐵”⟩) = (𝐴 ∪ {⟨(♯‘𝐴), 𝐵⟩}))

Proof of Theorem cats1un

Dummy variable 𝑥 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		ccatws1cl 11104	. . . . 5 ⊢ ((𝐴 ∈ Word 𝑋 ∧ 𝐵 ∈ 𝑋) → (𝐴 ++ ⟨“𝐵”⟩) ∈ Word 𝑋)
2		wrdf 11017	. . . . 5 ⊢ ((𝐴 ++ ⟨“𝐵”⟩) ∈ Word 𝑋 → (𝐴 ++ ⟨“𝐵”⟩):(0..^(♯‘(𝐴 ++ ⟨“𝐵”⟩)))⟶𝑋)
3	1, 2	syl 14	. . . 4 ⊢ ((𝐴 ∈ Word 𝑋 ∧ 𝐵 ∈ 𝑋) → (𝐴 ++ ⟨“𝐵”⟩):(0..^(♯‘(𝐴 ++ ⟨“𝐵”⟩)))⟶𝑋)
4		ccatws1leng 11106	. . . . . . 7 ⊢ ((𝐴 ∈ Word 𝑋 ∧ 𝐵 ∈ 𝑋) → (♯‘(𝐴 ++ ⟨“𝐵”⟩)) = ((♯‘𝐴) + 1))
5	4	oveq2d 5972	. . . . . 6 ⊢ ((𝐴 ∈ Word 𝑋 ∧ 𝐵 ∈ 𝑋) → (0..^(♯‘(𝐴 ++ ⟨“𝐵”⟩))) = (0..^((♯‘𝐴) + 1)))
6		lencl 11015	. . . . . . . . 9 ⊢ (𝐴 ∈ Word 𝑋 → (♯‘𝐴) ∈ ℕ0)
7		nn0uz 9698	. . . . . . . . 9 ⊢ ℕ0 = (ℤ≥‘0)
8	6, 7	eleqtrdi 2299	. . . . . . . 8 ⊢ (𝐴 ∈ Word 𝑋 → (♯‘𝐴) ∈ (ℤ≥‘0))
9		fzosplitsn 10379	. . . . . . . 8 ⊢ ((♯‘𝐴) ∈ (ℤ≥‘0) → (0..^((♯‘𝐴) + 1)) = ((0..^(♯‘𝐴)) ∪ {(♯‘𝐴)}))
10	8, 9	syl 14	. . . . . . 7 ⊢ (𝐴 ∈ Word 𝑋 → (0..^((♯‘𝐴) + 1)) = ((0..^(♯‘𝐴)) ∪ {(♯‘𝐴)}))
11	10	adantr 276	. . . . . 6 ⊢ ((𝐴 ∈ Word 𝑋 ∧ 𝐵 ∈ 𝑋) → (0..^((♯‘𝐴) + 1)) = ((0..^(♯‘𝐴)) ∪ {(♯‘𝐴)}))
12	5, 11	eqtrd 2239	. . . . 5 ⊢ ((𝐴 ∈ Word 𝑋 ∧ 𝐵 ∈ 𝑋) → (0..^(♯‘(𝐴 ++ ⟨“𝐵”⟩))) = ((0..^(♯‘𝐴)) ∪ {(♯‘𝐴)}))
13	12	feq2d 5422	. . . 4 ⊢ ((𝐴 ∈ Word 𝑋 ∧ 𝐵 ∈ 𝑋) → ((𝐴 ++ ⟨“𝐵”⟩):(0..^(♯‘(𝐴 ++ ⟨“𝐵”⟩)))⟶𝑋 ↔ (𝐴 ++ ⟨“𝐵”⟩):((0..^(♯‘𝐴)) ∪ {(♯‘𝐴)})⟶𝑋))
14	3, 13	mpbid 147	. . 3 ⊢ ((𝐴 ∈ Word 𝑋 ∧ 𝐵 ∈ 𝑋) → (𝐴 ++ ⟨“𝐵”⟩):((0..^(♯‘𝐴)) ∪ {(♯‘𝐴)})⟶𝑋)
15	14	ffnd 5435	. 2 ⊢ ((𝐴 ∈ Word 𝑋 ∧ 𝐵 ∈ 𝑋) → (𝐴 ++ ⟨“𝐵”⟩) Fn ((0..^(♯‘𝐴)) ∪ {(♯‘𝐴)}))
16		wrdf 11017	. . . . 5 ⊢ (𝐴 ∈ Word 𝑋 → 𝐴:(0..^(♯‘𝐴))⟶𝑋)
17	16	adantr 276	. . . 4 ⊢ ((𝐴 ∈ Word 𝑋 ∧ 𝐵 ∈ 𝑋) → 𝐴:(0..^(♯‘𝐴))⟶𝑋)
18		eqid 2206	. . . . . 6 ⊢ {⟨(♯‘𝐴), 𝐵⟩} = {⟨(♯‘𝐴), 𝐵⟩}
19		fsng 5765	. . . . . 6 ⊢ (((♯‘𝐴) ∈ ℕ0 ∧ 𝐵 ∈ 𝑋) → ({⟨(♯‘𝐴), 𝐵⟩}:{(♯‘𝐴)}⟶{𝐵} ↔ {⟨(♯‘𝐴), 𝐵⟩} = {⟨(♯‘𝐴), 𝐵⟩}))
20	18, 19	mpbiri 168	. . . . 5 ⊢ (((♯‘𝐴) ∈ ℕ0 ∧ 𝐵 ∈ 𝑋) → {⟨(♯‘𝐴), 𝐵⟩}:{(♯‘𝐴)}⟶{𝐵})
21	6, 20	sylan 283	. . . 4 ⊢ ((𝐴 ∈ Word 𝑋 ∧ 𝐵 ∈ 𝑋) → {⟨(♯‘𝐴), 𝐵⟩}:{(♯‘𝐴)}⟶{𝐵})
22		fzodisjsn 10321	. . . . 5 ⊢ ((0..^(♯‘𝐴)) ∩ {(♯‘𝐴)}) = ∅
23	22	a1i 9	. . . 4 ⊢ ((𝐴 ∈ Word 𝑋 ∧ 𝐵 ∈ 𝑋) → ((0..^(♯‘𝐴)) ∩ {(♯‘𝐴)}) = ∅)
24		fun 5458	. . . 4 ⊢ (((𝐴:(0..^(♯‘𝐴))⟶𝑋 ∧ {⟨(♯‘𝐴), 𝐵⟩}:{(♯‘𝐴)}⟶{𝐵}) ∧ ((0..^(♯‘𝐴)) ∩ {(♯‘𝐴)}) = ∅) → (𝐴 ∪ {⟨(♯‘𝐴), 𝐵⟩}):((0..^(♯‘𝐴)) ∪ {(♯‘𝐴)})⟶(𝑋 ∪ {𝐵}))
25	17, 21, 23, 24	syl21anc 1249	. . 3 ⊢ ((𝐴 ∈ Word 𝑋 ∧ 𝐵 ∈ 𝑋) → (𝐴 ∪ {⟨(♯‘𝐴), 𝐵⟩}):((0..^(♯‘𝐴)) ∪ {(♯‘𝐴)})⟶(𝑋 ∪ {𝐵}))
26	25	ffnd 5435	. 2 ⊢ ((𝐴 ∈ Word 𝑋 ∧ 𝐵 ∈ 𝑋) → (𝐴 ∪ {⟨(♯‘𝐴), 𝐵⟩}) Fn ((0..^(♯‘𝐴)) ∪ {(♯‘𝐴)}))
27		elun 3318	. . 3 ⊢ (𝑥 ∈ ((0..^(♯‘𝐴)) ∪ {(♯‘𝐴)}) ↔ (𝑥 ∈ (0..^(♯‘𝐴)) ∨ 𝑥 ∈ {(♯‘𝐴)}))
28		ccats1val1g 11109	. . . . . 6 ⊢ ((𝐴 ∈ Word 𝑋 ∧ 𝐵 ∈ 𝑋 ∧ 𝑥 ∈ (0..^(♯‘𝐴))) → ((𝐴 ++ ⟨“𝐵”⟩)‘𝑥) = (𝐴‘𝑥))
29	28	3expa 1206	. . . . 5 ⊢ (((𝐴 ∈ Word 𝑋 ∧ 𝐵 ∈ 𝑋) ∧ 𝑥 ∈ (0..^(♯‘𝐴))) → ((𝐴 ++ ⟨“𝐵”⟩)‘𝑥) = (𝐴‘𝑥))
30		vex 2776	. . . . . 6 ⊢ 𝑥 ∈ V
31		simpr 110	. . . . . . . 8 ⊢ (((𝐴 ∈ Word 𝑋 ∧ 𝐵 ∈ 𝑋) ∧ 𝑥 ∈ (0..^(♯‘𝐴))) → 𝑥 ∈ (0..^(♯‘𝐴)))
32		fzonel 10298	. . . . . . . 8 ⊢ ¬ (♯‘𝐴) ∈ (0..^(♯‘𝐴))
33		nelne2 2468	. . . . . . . 8 ⊢ ((𝑥 ∈ (0..^(♯‘𝐴)) ∧ ¬ (♯‘𝐴) ∈ (0..^(♯‘𝐴))) → 𝑥 ≠ (♯‘𝐴))
34	31, 32, 33	sylancl 413	. . . . . . 7 ⊢ (((𝐴 ∈ Word 𝑋 ∧ 𝐵 ∈ 𝑋) ∧ 𝑥 ∈ (0..^(♯‘𝐴))) → 𝑥 ≠ (♯‘𝐴))
35	34	necomd 2463	. . . . . 6 ⊢ (((𝐴 ∈ Word 𝑋 ∧ 𝐵 ∈ 𝑋) ∧ 𝑥 ∈ (0..^(♯‘𝐴))) → (♯‘𝐴) ≠ 𝑥)
36		fvunsng 5790	. . . . . 6 ⊢ ((𝑥 ∈ V ∧ (♯‘𝐴) ≠ 𝑥) → ((𝐴 ∪ {⟨(♯‘𝐴), 𝐵⟩})‘𝑥) = (𝐴‘𝑥))
37	30, 35, 36	sylancr 414	. . . . 5 ⊢ (((𝐴 ∈ Word 𝑋 ∧ 𝐵 ∈ 𝑋) ∧ 𝑥 ∈ (0..^(♯‘𝐴))) → ((𝐴 ∪ {⟨(♯‘𝐴), 𝐵⟩})‘𝑥) = (𝐴‘𝑥))
38	29, 37	eqtr4d 2242	. . . 4 ⊢ (((𝐴 ∈ Word 𝑋 ∧ 𝐵 ∈ 𝑋) ∧ 𝑥 ∈ (0..^(♯‘𝐴))) → ((𝐴 ++ ⟨“𝐵”⟩)‘𝑥) = ((𝐴 ∪ {⟨(♯‘𝐴), 𝐵⟩})‘𝑥))
39	6	elexd 2787	. . . . . . . . 9 ⊢ (𝐴 ∈ Word 𝑋 → (♯‘𝐴) ∈ V)
40	39	adantr 276	. . . . . . . 8 ⊢ ((𝐴 ∈ Word 𝑋 ∧ 𝐵 ∈ 𝑋) → (♯‘𝐴) ∈ V)
41		simpr 110	. . . . . . . 8 ⊢ ((𝐴 ∈ Word 𝑋 ∧ 𝐵 ∈ 𝑋) → 𝐵 ∈ 𝑋)
42	17	fdmd 5441	. . . . . . . . . 10 ⊢ ((𝐴 ∈ Word 𝑋 ∧ 𝐵 ∈ 𝑋) → dom 𝐴 = (0..^(♯‘𝐴)))
43	42	eleq2d 2276	. . . . . . . . 9 ⊢ ((𝐴 ∈ Word 𝑋 ∧ 𝐵 ∈ 𝑋) → ((♯‘𝐴) ∈ dom 𝐴 ↔ (♯‘𝐴) ∈ (0..^(♯‘𝐴))))
44	32, 43	mtbiri 677	. . . . . . . 8 ⊢ ((𝐴 ∈ Word 𝑋 ∧ 𝐵 ∈ 𝑋) → ¬ (♯‘𝐴) ∈ dom 𝐴)
45		fsnunfv 5797	. . . . . . . 8 ⊢ (((♯‘𝐴) ∈ V ∧ 𝐵 ∈ 𝑋 ∧ ¬ (♯‘𝐴) ∈ dom 𝐴) → ((𝐴 ∪ {⟨(♯‘𝐴), 𝐵⟩})‘(♯‘𝐴)) = 𝐵)
46	40, 41, 44, 45	syl3anc 1250	. . . . . . 7 ⊢ ((𝐴 ∈ Word 𝑋 ∧ 𝐵 ∈ 𝑋) → ((𝐴 ∪ {⟨(♯‘𝐴), 𝐵⟩})‘(♯‘𝐴)) = 𝐵)
47		simpl 109	. . . . . . . . 9 ⊢ ((𝐴 ∈ Word 𝑋 ∧ 𝐵 ∈ 𝑋) → 𝐴 ∈ Word 𝑋)
48		s1cl 11093	. . . . . . . . . 10 ⊢ (𝐵 ∈ 𝑋 → ⟨“𝐵”⟩ ∈ Word 𝑋)
49	48	adantl 277	. . . . . . . . 9 ⊢ ((𝐴 ∈ Word 𝑋 ∧ 𝐵 ∈ 𝑋) → ⟨“𝐵”⟩ ∈ Word 𝑋)
50		s1leng 11096	. . . . . . . . . . . 12 ⊢ (𝐵 ∈ 𝑋 → (♯‘⟨“𝐵”⟩) = 1)
51		1nn 9062	. . . . . . . . . . . 12 ⊢ 1 ∈ ℕ
52	50, 51	eqeltrdi 2297	. . . . . . . . . . 11 ⊢ (𝐵 ∈ 𝑋 → (♯‘⟨“𝐵”⟩) ∈ ℕ)
53		lbfzo0 10322	. . . . . . . . . . 11 ⊢ (0 ∈ (0..^(♯‘⟨“𝐵”⟩)) ↔ (♯‘⟨“𝐵”⟩) ∈ ℕ)
54	52, 53	sylibr 134	. . . . . . . . . 10 ⊢ (𝐵 ∈ 𝑋 → 0 ∈ (0..^(♯‘⟨“𝐵”⟩)))
55	54	adantl 277	. . . . . . . . 9 ⊢ ((𝐴 ∈ Word 𝑋 ∧ 𝐵 ∈ 𝑋) → 0 ∈ (0..^(♯‘⟨“𝐵”⟩)))
56		ccatval3 11073	. . . . . . . . 9 ⊢ ((𝐴 ∈ Word 𝑋 ∧ ⟨“𝐵”⟩ ∈ Word 𝑋 ∧ 0 ∈ (0..^(♯‘⟨“𝐵”⟩))) → ((𝐴 ++ ⟨“𝐵”⟩)‘(0 + (♯‘𝐴))) = (⟨“𝐵”⟩‘0))
57	47, 49, 55, 56	syl3anc 1250	. . . . . . . 8 ⊢ ((𝐴 ∈ Word 𝑋 ∧ 𝐵 ∈ 𝑋) → ((𝐴 ++ ⟨“𝐵”⟩)‘(0 + (♯‘𝐴))) = (⟨“𝐵”⟩‘0))
58		s1fv 11098	. . . . . . . . 9 ⊢ (𝐵 ∈ 𝑋 → (⟨“𝐵”⟩‘0) = 𝐵)
59	58	adantl 277	. . . . . . . 8 ⊢ ((𝐴 ∈ Word 𝑋 ∧ 𝐵 ∈ 𝑋) → (⟨“𝐵”⟩‘0) = 𝐵)
60	57, 59	eqtrd 2239	. . . . . . 7 ⊢ ((𝐴 ∈ Word 𝑋 ∧ 𝐵 ∈ 𝑋) → ((𝐴 ++ ⟨“𝐵”⟩)‘(0 + (♯‘𝐴))) = 𝐵)
61	6	adantr 276	. . . . . . . . . 10 ⊢ ((𝐴 ∈ Word 𝑋 ∧ 𝐵 ∈ 𝑋) → (♯‘𝐴) ∈ ℕ0)
62	61	nn0cnd 9365	. . . . . . . . 9 ⊢ ((𝐴 ∈ Word 𝑋 ∧ 𝐵 ∈ 𝑋) → (♯‘𝐴) ∈ ℂ)
63	62	addlidd 8237	. . . . . . . 8 ⊢ ((𝐴 ∈ Word 𝑋 ∧ 𝐵 ∈ 𝑋) → (0 + (♯‘𝐴)) = (♯‘𝐴))
64	63	fveq2d 5592	. . . . . . 7 ⊢ ((𝐴 ∈ Word 𝑋 ∧ 𝐵 ∈ 𝑋) → ((𝐴 ++ ⟨“𝐵”⟩)‘(0 + (♯‘𝐴))) = ((𝐴 ++ ⟨“𝐵”⟩)‘(♯‘𝐴)))
65	46, 60, 64	3eqtr2rd 2246	. . . . . 6 ⊢ ((𝐴 ∈ Word 𝑋 ∧ 𝐵 ∈ 𝑋) → ((𝐴 ++ ⟨“𝐵”⟩)‘(♯‘𝐴)) = ((𝐴 ∪ {⟨(♯‘𝐴), 𝐵⟩})‘(♯‘𝐴)))
66		elsni 3655	. . . . . . . 8 ⊢ (𝑥 ∈ {(♯‘𝐴)} → 𝑥 = (♯‘𝐴))
67	66	fveq2d 5592	. . . . . . 7 ⊢ (𝑥 ∈ {(♯‘𝐴)} → ((𝐴 ++ ⟨“𝐵”⟩)‘𝑥) = ((𝐴 ++ ⟨“𝐵”⟩)‘(♯‘𝐴)))
68	66	fveq2d 5592	. . . . . . 7 ⊢ (𝑥 ∈ {(♯‘𝐴)} → ((𝐴 ∪ {⟨(♯‘𝐴), 𝐵⟩})‘𝑥) = ((𝐴 ∪ {⟨(♯‘𝐴), 𝐵⟩})‘(♯‘𝐴)))
69	67, 68	eqeq12d 2221	. . . . . 6 ⊢ (𝑥 ∈ {(♯‘𝐴)} → (((𝐴 ++ ⟨“𝐵”⟩)‘𝑥) = ((𝐴 ∪ {⟨(♯‘𝐴), 𝐵⟩})‘𝑥) ↔ ((𝐴 ++ ⟨“𝐵”⟩)‘(♯‘𝐴)) = ((𝐴 ∪ {⟨(♯‘𝐴), 𝐵⟩})‘(♯‘𝐴))))
70	65, 69	syl5ibrcom 157	. . . . 5 ⊢ ((𝐴 ∈ Word 𝑋 ∧ 𝐵 ∈ 𝑋) → (𝑥 ∈ {(♯‘𝐴)} → ((𝐴 ++ ⟨“𝐵”⟩)‘𝑥) = ((𝐴 ∪ {⟨(♯‘𝐴), 𝐵⟩})‘𝑥)))
71	70	imp 124	. . . 4 ⊢ (((𝐴 ∈ Word 𝑋 ∧ 𝐵 ∈ 𝑋) ∧ 𝑥 ∈ {(♯‘𝐴)}) → ((𝐴 ++ ⟨“𝐵”⟩)‘𝑥) = ((𝐴 ∪ {⟨(♯‘𝐴), 𝐵⟩})‘𝑥))
72	38, 71	jaodan 799	. . 3 ⊢ (((𝐴 ∈ Word 𝑋 ∧ 𝐵 ∈ 𝑋) ∧ (𝑥 ∈ (0..^(♯‘𝐴)) ∨ 𝑥 ∈ {(♯‘𝐴)})) → ((𝐴 ++ ⟨“𝐵”⟩)‘𝑥) = ((𝐴 ∪ {⟨(♯‘𝐴), 𝐵⟩})‘𝑥))
73	27, 72	sylan2b 287	. 2 ⊢ (((𝐴 ∈ Word 𝑋 ∧ 𝐵 ∈ 𝑋) ∧ 𝑥 ∈ ((0..^(♯‘𝐴)) ∪ {(♯‘𝐴)})) → ((𝐴 ++ ⟨“𝐵”⟩)‘𝑥) = ((𝐴 ∪ {⟨(♯‘𝐴), 𝐵⟩})‘𝑥))
74	15, 26, 73	eqfnfvd 5692	1 ⊢ ((𝐴 ∈ Word 𝑋 ∧ 𝐵 ∈ 𝑋) → (𝐴 ++ ⟨“𝐵”⟩) = (𝐴 ∪ {⟨(♯‘𝐴), 𝐵⟩}))

Syntax hints:  ¬ wn 3   → wi 4   ∧ wa 104   ∨ wo 710   = wceq 1373   ∈ wcel 2177   ≠ wne 2377  Vcvv 2773   ∪ cun 3168   ∩ cin 3169  ∅c0 3464  {csn 3637  ⟨cop 3640  dom cdm 4682  ⟶wf 5275  ‘cfv 5279  (class class class)co 5956  0cc0 7940  1c1 7941   + caddc 7943  ℕcn 9051  ℕ₀cn0 9310  ℤ_≥cuz 9663  ..^cfzo 10279  ♯chash 10937  Word cword 11011   ++ cconcat 11064  ⟨“cs1 11087

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-in1 615  ax-in2 616  ax-io 711  ax-5 1471  ax-7 1472  ax-gen 1473  ax-ie1 1517  ax-ie2 1518  ax-8 1528  ax-10 1529  ax-11 1530  ax-i12 1531  ax-bndl 1533  ax-4 1534  ax-17 1550  ax-i9 1554  ax-ial 1558  ax-i5r 1559  ax-13 2179  ax-14 2180  ax-ext 2188  ax-coll 4166  ax-sep 4169  ax-nul 4177  ax-pow 4225  ax-pr 4260  ax-un 4487  ax-setind 4592  ax-iinf 4643  ax-cnex 8031  ax-resscn 8032  ax-1cn 8033  ax-1re 8034  ax-icn 8035  ax-addcl 8036  ax-addrcl 8037  ax-mulcl 8038  ax-addcom 8040  ax-addass 8042  ax-distr 8044  ax-i2m1 8045  ax-0lt1 8046  ax-0id 8048  ax-rnegex 8049  ax-cnre 8051  ax-pre-ltirr 8052  ax-pre-ltwlin 8053  ax-pre-lttrn 8054  ax-pre-apti 8055  ax-pre-ltadd 8056

This theorem depends on definitions:  df-bi 117  df-dc 837  df-3or 982  df-3an 983  df-tru 1376  df-fal 1379  df-nf 1485  df-sb 1787  df-eu 2058  df-mo 2059  df-clab 2193  df-cleq 2199  df-clel 2202  df-nfc 2338  df-ne 2378  df-nel 2473  df-ral 2490  df-rex 2491  df-reu 2492  df-rab 2494  df-v 2775  df-sbc 3003  df-csb 3098  df-dif 3172  df-un 3174  df-in 3176  df-ss 3183  df-nul 3465  df-if 3576  df-pw 3622  df-sn 3643  df-pr 3644  df-op 3646  df-uni 3856  df-int 3891  df-iun 3934  df-br 4051  df-opab 4113  df-mpt 4114  df-tr 4150  df-id 4347  df-iord 4420  df-on 4422  df-ilim 4423  df-suc 4425  df-iom 4646  df-xp 4688  df-rel 4689  df-cnv 4690  df-co 4691  df-dm 4692  df-rn 4693  df-res 4694  df-ima 4695  df-iota 5240  df-fun 5281  df-fn 5282  df-f 5283  df-f1 5284  df-fo 5285  df-f1o 5286  df-fv 5287  df-riota 5911  df-ov 5959  df-oprab 5960  df-mpo 5961  df-1st 6238  df-2nd 6239  df-recs 6403  df-frec 6489  df-1o 6514  df-er 6632  df-en 6840  df-dom 6841  df-fin 6842  df-pnf 8124  df-mnf 8125  df-xr 8126  df-ltxr 8127  df-le 8128  df-sub 8260  df-neg 8261  df-inn 9052  df-n0 9311  df-z 9388  df-uz 9664  df-fz 10146  df-fzo 10280  df-ihash 10938  df-word 11012  df-concat 11065  df-s1 11088

This theorem is referenced by: (None)