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Theorem chnub 18545

Description: In a chain, the last element is an upper bound. (Contributed by Thierry Arnoux, 19-Jun-2025.)

**Hypotheses**
Ref	Expression
chnub.1	⊢ (𝜑 → < Po 𝐴)
chnub.2	⊢ (𝜑 → 𝐶 ∈ ( < Chain 𝐴))
chnub.3	⊢ (𝜑 → 𝐼 ∈ (0..^((♯‘𝐶) − 1)))

**Assertion**
Ref	Expression
chnub	⊢ (𝜑 → (𝐶‘𝐼) < (lastS‘𝐶))

Proof of Theorem chnub Dummy variables 𝑐 𝑑 𝑥 𝑖 𝑗 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		fveq2 6834	. . 3 ⊢ (𝑖 = 𝐼 → (𝐶‘𝑖) = (𝐶‘𝐼))
2	1	breq1d 5108	. 2 ⊢ (𝑖 = 𝐼 → ((𝐶‘𝑖) < (lastS‘𝐶) ↔ (𝐶‘𝐼) < (lastS‘𝐶)))
3		fveq2 6834	. . . . . 6 ⊢ (𝑐 = ∅ → (♯‘𝑐) = (♯‘∅))
4	3	oveq1d 7373	. . . . 5 ⊢ (𝑐 = ∅ → ((♯‘𝑐) − 1) = ((♯‘∅) − 1))
5	4	oveq2d 7374	. . . 4 ⊢ (𝑐 = ∅ → (0..^((♯‘𝑐) − 1)) = (0..^((♯‘∅) − 1)))
6		fveq1 6833	. . . . 5 ⊢ (𝑐 = ∅ → (𝑐‘𝑖) = (∅‘𝑖))
7		fveq2 6834	. . . . 5 ⊢ (𝑐 = ∅ → (lastS‘𝑐) = (lastS‘∅))
8	6, 7	breq12d 5111	. . . 4 ⊢ (𝑐 = ∅ → ((𝑐‘𝑖) < (lastS‘𝑐) ↔ (∅‘𝑖) < (lastS‘∅)))
9	5, 8	raleqbidv 3316	. . 3 ⊢ (𝑐 = ∅ → (∀𝑖 ∈ (0..^((♯‘𝑐) − 1))(𝑐‘𝑖) < (lastS‘𝑐) ↔ ∀𝑖 ∈ (0..^((♯‘∅) − 1))(∅‘𝑖) < (lastS‘∅)))
10		fveq2 6834	. . . . . 6 ⊢ (𝑐 = 𝑑 → (♯‘𝑐) = (♯‘𝑑))
11	10	oveq1d 7373	. . . . 5 ⊢ (𝑐 = 𝑑 → ((♯‘𝑐) − 1) = ((♯‘𝑑) − 1))
12	11	oveq2d 7374	. . . 4 ⊢ (𝑐 = 𝑑 → (0..^((♯‘𝑐) − 1)) = (0..^((♯‘𝑑) − 1)))
13		fveq1 6833	. . . . 5 ⊢ (𝑐 = 𝑑 → (𝑐‘𝑖) = (𝑑‘𝑖))
14		fveq2 6834	. . . . 5 ⊢ (𝑐 = 𝑑 → (lastS‘𝑐) = (lastS‘𝑑))
15	13, 14	breq12d 5111	. . . 4 ⊢ (𝑐 = 𝑑 → ((𝑐‘𝑖) < (lastS‘𝑐) ↔ (𝑑‘𝑖) < (lastS‘𝑑)))
16	12, 15	raleqbidv 3316	. . 3 ⊢ (𝑐 = 𝑑 → (∀𝑖 ∈ (0..^((♯‘𝑐) − 1))(𝑐‘𝑖) < (lastS‘𝑐) ↔ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)))
17		fveq2 6834	. . . . . 6 ⊢ (𝑖 = 𝑗 → (𝑐‘𝑖) = (𝑐‘𝑗))
18	17	breq1d 5108	. . . . 5 ⊢ (𝑖 = 𝑗 → ((𝑐‘𝑖) < (lastS‘𝑐) ↔ (𝑐‘𝑗) < (lastS‘𝑐)))
19	18	cbvralvw 3214	. . . 4 ⊢ (∀𝑖 ∈ (0..^((♯‘𝑐) − 1))(𝑐‘𝑖) < (lastS‘𝑐) ↔ ∀𝑗 ∈ (0..^((♯‘𝑐) − 1))(𝑐‘𝑗) < (lastS‘𝑐))
20		fveq2 6834	. . . . . . 7 ⊢ (𝑐 = (𝑑 ++ ⟨“𝑥”⟩) → (♯‘𝑐) = (♯‘(𝑑 ++ ⟨“𝑥”⟩)))
21	20	oveq1d 7373	. . . . . 6 ⊢ (𝑐 = (𝑑 ++ ⟨“𝑥”⟩) → ((♯‘𝑐) − 1) = ((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))
22	21	oveq2d 7374	. . . . 5 ⊢ (𝑐 = (𝑑 ++ ⟨“𝑥”⟩) → (0..^((♯‘𝑐) − 1)) = (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1)))
23		fveq1 6833	. . . . . 6 ⊢ (𝑐 = (𝑑 ++ ⟨“𝑥”⟩) → (𝑐‘𝑗) = ((𝑑 ++ ⟨“𝑥”⟩)‘𝑗))
24		fveq2 6834	. . . . . 6 ⊢ (𝑐 = (𝑑 ++ ⟨“𝑥”⟩) → (lastS‘𝑐) = (lastS‘(𝑑 ++ ⟨“𝑥”⟩)))
25	23, 24	breq12d 5111	. . . . 5 ⊢ (𝑐 = (𝑑 ++ ⟨“𝑥”⟩) → ((𝑐‘𝑗) < (lastS‘𝑐) ↔ ((𝑑 ++ ⟨“𝑥”⟩)‘𝑗) < (lastS‘(𝑑 ++ ⟨“𝑥”⟩))))
26	22, 25	raleqbidv 3316	. . . 4 ⊢ (𝑐 = (𝑑 ++ ⟨“𝑥”⟩) → (∀𝑗 ∈ (0..^((♯‘𝑐) − 1))(𝑐‘𝑗) < (lastS‘𝑐) ↔ ∀𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))((𝑑 ++ ⟨“𝑥”⟩)‘𝑗) < (lastS‘(𝑑 ++ ⟨“𝑥”⟩))))
27	19, 26	bitrid 283	. . 3 ⊢ (𝑐 = (𝑑 ++ ⟨“𝑥”⟩) → (∀𝑖 ∈ (0..^((♯‘𝑐) − 1))(𝑐‘𝑖) < (lastS‘𝑐) ↔ ∀𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))((𝑑 ++ ⟨“𝑥”⟩)‘𝑗) < (lastS‘(𝑑 ++ ⟨“𝑥”⟩))))
28		fveq2 6834	. . . . . 6 ⊢ (𝑐 = 𝐶 → (♯‘𝑐) = (♯‘𝐶))
29	28	oveq1d 7373	. . . . 5 ⊢ (𝑐 = 𝐶 → ((♯‘𝑐) − 1) = ((♯‘𝐶) − 1))
30	29	oveq2d 7374	. . . 4 ⊢ (𝑐 = 𝐶 → (0..^((♯‘𝑐) − 1)) = (0..^((♯‘𝐶) − 1)))
31		fveq1 6833	. . . . 5 ⊢ (𝑐 = 𝐶 → (𝑐‘𝑖) = (𝐶‘𝑖))
32		fveq2 6834	. . . . 5 ⊢ (𝑐 = 𝐶 → (lastS‘𝑐) = (lastS‘𝐶))
33	31, 32	breq12d 5111	. . . 4 ⊢ (𝑐 = 𝐶 → ((𝑐‘𝑖) < (lastS‘𝑐) ↔ (𝐶‘𝑖) < (lastS‘𝐶)))
34	30, 33	raleqbidv 3316	. . 3 ⊢ (𝑐 = 𝐶 → (∀𝑖 ∈ (0..^((♯‘𝑐) − 1))(𝑐‘𝑖) < (lastS‘𝑐) ↔ ∀𝑖 ∈ (0..^((♯‘𝐶) − 1))(𝐶‘𝑖) < (lastS‘𝐶)))
35		chnub.2	. . 3 ⊢ (𝜑 → 𝐶 ∈ ( < Chain 𝐴))
36		ral0 4451	. . . . 5 ⊢ ∀𝑖 ∈ ∅ (∅‘𝑖) < (lastS‘∅)
37		hash0 14290	. . . . . . . . 9 ⊢ (♯‘∅) = 0
38	37	oveq1i 7368	. . . . . . . 8 ⊢ ((♯‘∅) − 1) = (0 − 1)
39		df-neg 11367	. . . . . . . . 9 ⊢ -1 = (0 − 1)
40		neg1rr 12131	. . . . . . . . . 10 ⊢ -1 ∈ ℝ
41		0re 11134	. . . . . . . . . 10 ⊢ 0 ∈ ℝ
42		neg1lt0 12133	. . . . . . . . . 10 ⊢ -1 < 0
43	40, 41, 42	ltleii 11256	. . . . . . . . 9 ⊢ -1 ≤ 0
44	39, 43	eqbrtrri 5121	. . . . . . . 8 ⊢ (0 − 1) ≤ 0
45	38, 44	eqbrtri 5119	. . . . . . 7 ⊢ ((♯‘∅) − 1) ≤ 0
46		0z 12499	. . . . . . . 8 ⊢ 0 ∈ ℤ
47	37, 46	eqeltri 2832	. . . . . . . . 9 ⊢ (♯‘∅) ∈ ℤ
48		1z 12521	. . . . . . . . 9 ⊢ 1 ∈ ℤ
49		zsubcl 12533	. . . . . . . . 9 ⊢ (((♯‘∅) ∈ ℤ ∧ 1 ∈ ℤ) → ((♯‘∅) − 1) ∈ ℤ)
50	47, 48, 49	mp2an 692	. . . . . . . 8 ⊢ ((♯‘∅) − 1) ∈ ℤ
51		fzon 13596	. . . . . . . 8 ⊢ ((0 ∈ ℤ ∧ ((♯‘∅) − 1) ∈ ℤ) → (((♯‘∅) − 1) ≤ 0 ↔ (0..^((♯‘∅) − 1)) = ∅))
52	46, 50, 51	mp2an 692	. . . . . . 7 ⊢ (((♯‘∅) − 1) ≤ 0 ↔ (0..^((♯‘∅) − 1)) = ∅)
53	45, 52	mpbi 230	. . . . . 6 ⊢ (0..^((♯‘∅) − 1)) = ∅
54	53	raleqi 3294	. . . . 5 ⊢ (∀𝑖 ∈ (0..^((♯‘∅) − 1))(∅‘𝑖) < (lastS‘∅) ↔ ∀𝑖 ∈ ∅ (∅‘𝑖) < (lastS‘∅))
55	36, 54	mpbir 231	. . . 4 ⊢ ∀𝑖 ∈ (0..^((♯‘∅) − 1))(∅‘𝑖) < (lastS‘∅)
56	55	a1i 11	. . 3 ⊢ (𝜑 → ∀𝑖 ∈ (0..^((♯‘∅) − 1))(∅‘𝑖) < (lastS‘∅))
57		simp-6r 787	. . . . . . . . . . . . 13 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 = ∅) → 𝑑 ∈ ( < Chain 𝐴))
58	57	chnwrd 18531	. . . . . . . . . . . 12 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 = ∅) → 𝑑 ∈ Word 𝐴)
59		ccatws1len 14544	. . . . . . . . . . . 12 ⊢ (𝑑 ∈ Word 𝐴 → (♯‘(𝑑 ++ ⟨“𝑥”⟩)) = ((♯‘𝑑) + 1))
60	58, 59	syl 17	. . . . . . . . . . 11 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 = ∅) → (♯‘(𝑑 ++ ⟨“𝑥”⟩)) = ((♯‘𝑑) + 1))
61		simpr 484	. . . . . . . . . . . . . 14 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 = ∅) → 𝑑 = ∅)
62	61	fveq2d 6838	. . . . . . . . . . . . 13 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 = ∅) → (♯‘𝑑) = (♯‘∅))
63	62, 37	eqtrdi 2787	. . . . . . . . . . . 12 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 = ∅) → (♯‘𝑑) = 0)
64	63	oveq1d 7373	. . . . . . . . . . 11 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 = ∅) → ((♯‘𝑑) + 1) = (0 + 1))
65		0p1e1 12262	. . . . . . . . . . . 12 ⊢ (0 + 1) = 1
66	65	a1i 11	. . . . . . . . . . 11 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 = ∅) → (0 + 1) = 1)
67	60, 64, 66	3eqtrd 2775	. . . . . . . . . 10 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 = ∅) → (♯‘(𝑑 ++ ⟨“𝑥”⟩)) = 1)
68	67	oveq1d 7373	. . . . . . . . 9 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 = ∅) → ((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1) = (1 − 1))
69		1m1e0 12217	. . . . . . . . 9 ⊢ (1 − 1) = 0
70	68, 69	eqtrdi 2787	. . . . . . . 8 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 = ∅) → ((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1) = 0)
71	70	oveq2d 7374	. . . . . . 7 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 = ∅) → (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1)) = (0..^0))
72		fzo0 13599	. . . . . . 7 ⊢ (0..^0) = ∅
73	71, 72	eqtrdi 2787	. . . . . 6 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 = ∅) → (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1)) = ∅)
74		simplr 768	. . . . . . 7 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 = ∅) → 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1)))
75	74	ne0d 4294	. . . . . 6 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 = ∅) → (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1)) ≠ ∅)
76	73, 75	pm2.21ddne 3016	. . . . 5 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 = ∅) → ((𝑑 ++ ⟨“𝑥”⟩)‘𝑗) < (lastS‘(𝑑 ++ ⟨“𝑥”⟩)))
77		chnub.1	. . . . . . . 8 ⊢ (𝜑 → < Po 𝐴)
78	77	ad7antr 738	. . . . . . 7 ⊢ ((((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) ∧ 𝑗 ∈ (0..^((♯‘𝑑) − 1))) → < Po 𝐴)
79		simp-6r 787	. . . . . . . . . . . 12 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) → 𝑑 ∈ ( < Chain 𝐴))
80	79	chnwrd 18531	. . . . . . . . . . 11 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) → 𝑑 ∈ Word 𝐴)
81	80	adantr 480	. . . . . . . . . 10 ⊢ ((((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) ∧ 𝑗 ∈ (0..^((♯‘𝑑) − 1))) → 𝑑 ∈ Word 𝐴)
82		simp-5r 785	. . . . . . . . . . 11 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) → 𝑥 ∈ 𝐴)
83	82	adantr 480	. . . . . . . . . 10 ⊢ ((((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) ∧ 𝑗 ∈ (0..^((♯‘𝑑) − 1))) → 𝑥 ∈ 𝐴)
84		ccatws1cl 14540	. . . . . . . . . 10 ⊢ ((𝑑 ∈ Word 𝐴 ∧ 𝑥 ∈ 𝐴) → (𝑑 ++ ⟨“𝑥”⟩) ∈ Word 𝐴)
85	81, 83, 84	syl2anc 584	. . . . . . . . 9 ⊢ ((((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) ∧ 𝑗 ∈ (0..^((♯‘𝑑) − 1))) → (𝑑 ++ ⟨“𝑥”⟩) ∈ Word 𝐴)
86		lencl 14456	. . . . . . . . . . . . . . . 16 ⊢ (𝑑 ∈ Word 𝐴 → (♯‘𝑑) ∈ ℕ₀)
87	80, 86	syl 17	. . . . . . . . . . . . . . 15 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) → (♯‘𝑑) ∈ ℕ₀)
88	87	nn0zd 12513	. . . . . . . . . . . . . 14 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) → (♯‘𝑑) ∈ ℤ)
89		1zzd 12522	. . . . . . . . . . . . . 14 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) → 1 ∈ ℤ)
90	88, 89	zsubcld 12601	. . . . . . . . . . . . 13 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) → ((♯‘𝑑) − 1) ∈ ℤ)
91	88	peano2zd 12599	. . . . . . . . . . . . 13 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) → ((♯‘𝑑) + 1) ∈ ℤ)
92	90	zred 12596	. . . . . . . . . . . . . 14 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) → ((♯‘𝑑) − 1) ∈ ℝ)
93	91	zred 12596	. . . . . . . . . . . . . 14 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) → ((♯‘𝑑) + 1) ∈ ℝ)
94		simpr 484	. . . . . . . . . . . . . . . . . 18 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) → 𝑑 ≠ ∅)
95		hasheq0 14286	. . . . . . . . . . . . . . . . . . . 20 ⊢ (𝑑 ∈ Word 𝐴 → ((♯‘𝑑) = 0 ↔ 𝑑 = ∅))
96	95	necon3bid 2976	. . . . . . . . . . . . . . . . . . 19 ⊢ (𝑑 ∈ Word 𝐴 → ((♯‘𝑑) ≠ 0 ↔ 𝑑 ≠ ∅))
97	96	biimpar 477	. . . . . . . . . . . . . . . . . 18 ⊢ ((𝑑 ∈ Word 𝐴 ∧ 𝑑 ≠ ∅) → (♯‘𝑑) ≠ 0)
98	80, 94, 97	syl2anc 584	. . . . . . . . . . . . . . . . 17 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) → (♯‘𝑑) ≠ 0)
99		elnnne0 12415	. . . . . . . . . . . . . . . . 17 ⊢ ((♯‘𝑑) ∈ ℕ ↔ ((♯‘𝑑) ∈ ℕ₀ ∧ (♯‘𝑑) ≠ 0))
100	87, 98, 99	sylanbrc 583	. . . . . . . . . . . . . . . 16 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) → (♯‘𝑑) ∈ ℕ)
101	100	nnred 12160	. . . . . . . . . . . . . . 15 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) → (♯‘𝑑) ∈ ℝ)
102	101	ltm1d 12074	. . . . . . . . . . . . . . 15 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) → ((♯‘𝑑) − 1) < (♯‘𝑑))
103	101	ltp1d 12072	. . . . . . . . . . . . . . 15 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) → (♯‘𝑑) < ((♯‘𝑑) + 1))
104	92, 101, 93, 102, 103	lttrd 11294	. . . . . . . . . . . . . 14 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) → ((♯‘𝑑) − 1) < ((♯‘𝑑) + 1))
105	92, 93, 104	ltled 11281	. . . . . . . . . . . . 13 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) → ((♯‘𝑑) − 1) ≤ ((♯‘𝑑) + 1))
106		eluz2 12757	. . . . . . . . . . . . 13 ⊢ (((♯‘𝑑) + 1) ∈ (ℤ_≥‘((♯‘𝑑) − 1)) ↔ (((♯‘𝑑) − 1) ∈ ℤ ∧ ((♯‘𝑑) + 1) ∈ ℤ ∧ ((♯‘𝑑) − 1) ≤ ((♯‘𝑑) + 1)))
107	90, 91, 105, 106	syl3anbrc 1344	. . . . . . . . . . . 12 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) → ((♯‘𝑑) + 1) ∈ (ℤ_≥‘((♯‘𝑑) − 1)))
108		fzoss2 13603	. . . . . . . . . . . 12 ⊢ (((♯‘𝑑) + 1) ∈ (ℤ_≥‘((♯‘𝑑) − 1)) → (0..^((♯‘𝑑) − 1)) ⊆ (0..^((♯‘𝑑) + 1)))
109	107, 108	syl 17	. . . . . . . . . . 11 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) → (0..^((♯‘𝑑) − 1)) ⊆ (0..^((♯‘𝑑) + 1)))
110	109	sselda 3933	. . . . . . . . . 10 ⊢ ((((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) ∧ 𝑗 ∈ (0..^((♯‘𝑑) − 1))) → 𝑗 ∈ (0..^((♯‘𝑑) + 1)))
111	81, 59	syl 17	. . . . . . . . . . 11 ⊢ ((((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) ∧ 𝑗 ∈ (0..^((♯‘𝑑) − 1))) → (♯‘(𝑑 ++ ⟨“𝑥”⟩)) = ((♯‘𝑑) + 1))
112	111	oveq2d 7374	. . . . . . . . . 10 ⊢ ((((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) ∧ 𝑗 ∈ (0..^((♯‘𝑑) − 1))) → (0..^(♯‘(𝑑 ++ ⟨“𝑥”⟩))) = (0..^((♯‘𝑑) + 1)))
113	110, 112	eleqtrrd 2839	. . . . . . . . 9 ⊢ ((((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) ∧ 𝑗 ∈ (0..^((♯‘𝑑) − 1))) → 𝑗 ∈ (0..^(♯‘(𝑑 ++ ⟨“𝑥”⟩))))
114		wrdsymbcl 14450	. . . . . . . . 9 ⊢ (((𝑑 ++ ⟨“𝑥”⟩) ∈ Word 𝐴 ∧ 𝑗 ∈ (0..^(♯‘(𝑑 ++ ⟨“𝑥”⟩)))) → ((𝑑 ++ ⟨“𝑥”⟩)‘𝑗) ∈ 𝐴)
115	85, 113, 114	syl2anc 584	. . . . . . . 8 ⊢ ((((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) ∧ 𝑗 ∈ (0..^((♯‘𝑑) − 1))) → ((𝑑 ++ ⟨“𝑥”⟩)‘𝑗) ∈ 𝐴)
116		simplr 768	. . . . . . . . 9 ⊢ ((((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) ∧ 𝑗 ∈ (0..^((♯‘𝑑) − 1))) → 𝑑 ≠ ∅)
117		lswcl 14491	. . . . . . . . 9 ⊢ ((𝑑 ∈ Word 𝐴 ∧ 𝑑 ≠ ∅) → (lastS‘𝑑) ∈ 𝐴)
118	81, 116, 117	syl2anc 584	. . . . . . . 8 ⊢ ((((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) ∧ 𝑗 ∈ (0..^((♯‘𝑑) − 1))) → (lastS‘𝑑) ∈ 𝐴)
119		lswccats1 14558	. . . . . . . . . . 11 ⊢ ((𝑑 ∈ Word 𝐴 ∧ 𝑥 ∈ 𝐴) → (lastS‘(𝑑 ++ ⟨“𝑥”⟩)) = 𝑥)
120	80, 82, 119	syl2anc 584	. . . . . . . . . 10 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) → (lastS‘(𝑑 ++ ⟨“𝑥”⟩)) = 𝑥)
121	120	adantr 480	. . . . . . . . 9 ⊢ ((((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) ∧ 𝑗 ∈ (0..^((♯‘𝑑) − 1))) → (lastS‘(𝑑 ++ ⟨“𝑥”⟩)) = 𝑥)
122	121, 83	eqeltrd 2836	. . . . . . . 8 ⊢ ((((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) ∧ 𝑗 ∈ (0..^((♯‘𝑑) − 1))) → (lastS‘(𝑑 ++ ⟨“𝑥”⟩)) ∈ 𝐴)
123	115, 118, 122	3jca 1128	. . . . . . 7 ⊢ ((((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) ∧ 𝑗 ∈ (0..^((♯‘𝑑) − 1))) → (((𝑑 ++ ⟨“𝑥”⟩)‘𝑗) ∈ 𝐴 ∧ (lastS‘𝑑) ∈ 𝐴 ∧ (lastS‘(𝑑 ++ ⟨“𝑥”⟩)) ∈ 𝐴))
124		simplr 768	. . . . . . . . . . 11 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) → 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1)))
125	59	oveq1d 7373	. . . . . . . . . . . . . 14 ⊢ (𝑑 ∈ Word 𝐴 → ((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1) = (((♯‘𝑑) + 1) − 1))
126	80, 125	syl 17	. . . . . . . . . . . . 13 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) → ((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1) = (((♯‘𝑑) + 1) − 1))
127	100	nncnd 12161	. . . . . . . . . . . . . 14 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) → (♯‘𝑑) ∈ ℂ)
128		1cnd 11127	. . . . . . . . . . . . . 14 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) → 1 ∈ ℂ)
129	127, 128	pncand 11493	. . . . . . . . . . . . 13 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) → (((♯‘𝑑) + 1) − 1) = (♯‘𝑑))
130	126, 129	eqtrd 2771	. . . . . . . . . . . 12 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) → ((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1) = (♯‘𝑑))
131	130	oveq2d 7374	. . . . . . . . . . 11 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) → (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1)) = (0..^(♯‘𝑑)))
132	124, 131	eleqtrd 2838	. . . . . . . . . 10 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) → 𝑗 ∈ (0..^(♯‘𝑑)))
133	132	adantr 480	. . . . . . . . 9 ⊢ ((((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) ∧ 𝑗 ∈ (0..^((♯‘𝑑) − 1))) → 𝑗 ∈ (0..^(♯‘𝑑)))
134		ccats1val1 14550	. . . . . . . . 9 ⊢ ((𝑑 ∈ Word 𝐴 ∧ 𝑗 ∈ (0..^(♯‘𝑑))) → ((𝑑 ++ ⟨“𝑥”⟩)‘𝑗) = (𝑑‘𝑗))
135	81, 133, 134	syl2anc 584	. . . . . . . 8 ⊢ ((((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) ∧ 𝑗 ∈ (0..^((♯‘𝑑) − 1))) → ((𝑑 ++ ⟨“𝑥”⟩)‘𝑗) = (𝑑‘𝑗))
136		fveq2 6834	. . . . . . . . . 10 ⊢ (𝑖 = 𝑗 → (𝑑‘𝑖) = (𝑑‘𝑗))
137	136	breq1d 5108	. . . . . . . . 9 ⊢ (𝑖 = 𝑗 → ((𝑑‘𝑖) < (lastS‘𝑑) ↔ (𝑑‘𝑗) < (lastS‘𝑑)))
138		simp-4r 783	. . . . . . . . 9 ⊢ ((((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) ∧ 𝑗 ∈ (0..^((♯‘𝑑) − 1))) → ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑))
139		simpr 484	. . . . . . . . 9 ⊢ ((((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) ∧ 𝑗 ∈ (0..^((♯‘𝑑) − 1))) → 𝑗 ∈ (0..^((♯‘𝑑) − 1)))
140	137, 138, 139	rspcdva 3577	. . . . . . . 8 ⊢ ((((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) ∧ 𝑗 ∈ (0..^((♯‘𝑑) − 1))) → (𝑑‘𝑗) < (lastS‘𝑑))
141	135, 140	eqbrtrd 5120	. . . . . . 7 ⊢ ((((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) ∧ 𝑗 ∈ (0..^((♯‘𝑑) − 1))) → ((𝑑 ++ ⟨“𝑥”⟩)‘𝑗) < (lastS‘𝑑))
142		simp-4r 783	. . . . . . . . . 10 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) → (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥))
143	94	neneqd 2937	. . . . . . . . . 10 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) → ¬ 𝑑 = ∅)
144	142, 143	orcnd 878	. . . . . . . . 9 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) → (lastS‘𝑑) < 𝑥)
145	144	adantr 480	. . . . . . . 8 ⊢ ((((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) ∧ 𝑗 ∈ (0..^((♯‘𝑑) − 1))) → (lastS‘𝑑) < 𝑥)
146	145, 121	breqtrrd 5126	. . . . . . 7 ⊢ ((((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) ∧ 𝑗 ∈ (0..^((♯‘𝑑) − 1))) → (lastS‘𝑑) < (lastS‘(𝑑 ++ ⟨“𝑥”⟩)))
147		potr 5545	. . . . . . . 8 ⊢ (( < Po 𝐴 ∧ (((𝑑 ++ ⟨“𝑥”⟩)‘𝑗) ∈ 𝐴 ∧ (lastS‘𝑑) ∈ 𝐴 ∧ (lastS‘(𝑑 ++ ⟨“𝑥”⟩)) ∈ 𝐴)) → ((((𝑑 ++ ⟨“𝑥”⟩)‘𝑗) < (lastS‘𝑑) ∧ (lastS‘𝑑) < (lastS‘(𝑑 ++ ⟨“𝑥”⟩))) → ((𝑑 ++ ⟨“𝑥”⟩)‘𝑗) < (lastS‘(𝑑 ++ ⟨“𝑥”⟩))))
148	147	imp 406	. . . . . . 7 ⊢ ((( < Po 𝐴 ∧ (((𝑑 ++ ⟨“𝑥”⟩)‘𝑗) ∈ 𝐴 ∧ (lastS‘𝑑) ∈ 𝐴 ∧ (lastS‘(𝑑 ++ ⟨“𝑥”⟩)) ∈ 𝐴)) ∧ (((𝑑 ++ ⟨“𝑥”⟩)‘𝑗) < (lastS‘𝑑) ∧ (lastS‘𝑑) < (lastS‘(𝑑 ++ ⟨“𝑥”⟩)))) → ((𝑑 ++ ⟨“𝑥”⟩)‘𝑗) < (lastS‘(𝑑 ++ ⟨“𝑥”⟩)))
149	78, 123, 141, 146, 148	syl22anc 838	. . . . . 6 ⊢ ((((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) ∧ 𝑗 ∈ (0..^((♯‘𝑑) − 1))) → ((𝑑 ++ ⟨“𝑥”⟩)‘𝑗) < (lastS‘(𝑑 ++ ⟨“𝑥”⟩)))
150	144	adantr 480	. . . . . . 7 ⊢ ((((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) ∧ 𝑗 = ((♯‘𝑑) − 1)) → (lastS‘𝑑) < 𝑥)
151	80	adantr 480	. . . . . . . . 9 ⊢ ((((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) ∧ 𝑗 = ((♯‘𝑑) − 1)) → 𝑑 ∈ Word 𝐴)
152		simp-6r 787	. . . . . . . . . 10 ⊢ ((((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) ∧ 𝑗 = ((♯‘𝑑) − 1)) → 𝑥 ∈ 𝐴)
153	152	s1cld 14527	. . . . . . . . 9 ⊢ ((((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) ∧ 𝑗 = ((♯‘𝑑) − 1)) → ⟨“𝑥”⟩ ∈ Word 𝐴)
154	100	adantr 480	. . . . . . . . . 10 ⊢ ((((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) ∧ 𝑗 = ((♯‘𝑑) − 1)) → (♯‘𝑑) ∈ ℕ)
155		fzo0end 13674	. . . . . . . . . 10 ⊢ ((♯‘𝑑) ∈ ℕ → ((♯‘𝑑) − 1) ∈ (0..^(♯‘𝑑)))
156	154, 155	syl 17	. . . . . . . . 9 ⊢ ((((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) ∧ 𝑗 = ((♯‘𝑑) − 1)) → ((♯‘𝑑) − 1) ∈ (0..^(♯‘𝑑)))
157		ccatval1 14500	. . . . . . . . 9 ⊢ ((𝑑 ∈ Word 𝐴 ∧ ⟨“𝑥”⟩ ∈ Word 𝐴 ∧ ((♯‘𝑑) − 1) ∈ (0..^(♯‘𝑑))) → ((𝑑 ++ ⟨“𝑥”⟩)‘((♯‘𝑑) − 1)) = (𝑑‘((♯‘𝑑) − 1)))
158	151, 153, 156, 157	syl3anc 1373	. . . . . . . 8 ⊢ ((((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) ∧ 𝑗 = ((♯‘𝑑) − 1)) → ((𝑑 ++ ⟨“𝑥”⟩)‘((♯‘𝑑) − 1)) = (𝑑‘((♯‘𝑑) − 1)))
159		simpr 484	. . . . . . . . 9 ⊢ ((((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) ∧ 𝑗 = ((♯‘𝑑) − 1)) → 𝑗 = ((♯‘𝑑) − 1))
160	159	fveq2d 6838	. . . . . . . 8 ⊢ ((((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) ∧ 𝑗 = ((♯‘𝑑) − 1)) → ((𝑑 ++ ⟨“𝑥”⟩)‘𝑗) = ((𝑑 ++ ⟨“𝑥”⟩)‘((♯‘𝑑) − 1)))
161		lsw 14487	. . . . . . . . 9 ⊢ (𝑑 ∈ Word 𝐴 → (lastS‘𝑑) = (𝑑‘((♯‘𝑑) − 1)))
162	151, 161	syl 17	. . . . . . . 8 ⊢ ((((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) ∧ 𝑗 = ((♯‘𝑑) − 1)) → (lastS‘𝑑) = (𝑑‘((♯‘𝑑) − 1)))
163	158, 160, 162	3eqtr4d 2781	. . . . . . 7 ⊢ ((((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) ∧ 𝑗 = ((♯‘𝑑) − 1)) → ((𝑑 ++ ⟨“𝑥”⟩)‘𝑗) = (lastS‘𝑑))
164	120	adantr 480	. . . . . . 7 ⊢ ((((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) ∧ 𝑗 = ((♯‘𝑑) − 1)) → (lastS‘(𝑑 ++ ⟨“𝑥”⟩)) = 𝑥)
165	150, 163, 164	3brtr4d 5130	. . . . . 6 ⊢ ((((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) ∧ 𝑗 = ((♯‘𝑑) − 1)) → ((𝑑 ++ ⟨“𝑥”⟩)‘𝑗) < (lastS‘(𝑑 ++ ⟨“𝑥”⟩)))
166	65	fveq2i 6837	. . . . . . . . . . 11 ⊢ (ℤ_≥‘(0 + 1)) = (ℤ_≥‘1)
167		nnuz 12790	. . . . . . . . . . 11 ⊢ ℕ = (ℤ_≥‘1)
168	166, 167	eqtr4i 2762	. . . . . . . . . 10 ⊢ (ℤ_≥‘(0 + 1)) = ℕ
169	100, 168	eleqtrrdi 2847	. . . . . . . . 9 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) → (♯‘𝑑) ∈ (ℤ_≥‘(0 + 1)))
170		fzosplitsnm1 13656	. . . . . . . . 9 ⊢ ((0 ∈ ℤ ∧ (♯‘𝑑) ∈ (ℤ_≥‘(0 + 1))) → (0..^(♯‘𝑑)) = ((0..^((♯‘𝑑) − 1)) ∪ {((♯‘𝑑) − 1)}))
171	46, 169, 170	sylancr 587	. . . . . . . 8 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) → (0..^(♯‘𝑑)) = ((0..^((♯‘𝑑) − 1)) ∪ {((♯‘𝑑) − 1)}))
172	132, 171	eleqtrd 2838	. . . . . . 7 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) → 𝑗 ∈ ((0..^((♯‘𝑑) − 1)) ∪ {((♯‘𝑑) − 1)}))
173		elunsn 4640	. . . . . . . 8 ⊢ (𝑗 ∈ ((0..^((♯‘𝑑) − 1)) ∪ {((♯‘𝑑) − 1)}) → (𝑗 ∈ ((0..^((♯‘𝑑) − 1)) ∪ {((♯‘𝑑) − 1)}) ↔ (𝑗 ∈ (0..^((♯‘𝑑) − 1)) ∨ 𝑗 = ((♯‘𝑑) − 1))))
174	173	ibi 267	. . . . . . 7 ⊢ (𝑗 ∈ ((0..^((♯‘𝑑) − 1)) ∪ {((♯‘𝑑) − 1)}) → (𝑗 ∈ (0..^((♯‘𝑑) − 1)) ∨ 𝑗 = ((♯‘𝑑) − 1)))
175	172, 174	syl 17	. . . . . 6 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) → (𝑗 ∈ (0..^((♯‘𝑑) − 1)) ∨ 𝑗 = ((♯‘𝑑) − 1)))
176	149, 165, 175	mpjaodan 960	. . . . 5 ⊢ (((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) ∧ 𝑑 ≠ ∅) → ((𝑑 ++ ⟨“𝑥”⟩)‘𝑗) < (lastS‘(𝑑 ++ ⟨“𝑥”⟩)))
177	76, 176	pm2.61dane 3019	. . . 4 ⊢ ((((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) ∧ 𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))) → ((𝑑 ++ ⟨“𝑥”⟩)‘𝑗) < (lastS‘(𝑑 ++ ⟨“𝑥”⟩)))
178	177	ralrimiva 3128	. . 3 ⊢ (((((𝜑 ∧ 𝑑 ∈ ( < Chain 𝐴)) ∧ 𝑥 ∈ 𝐴) ∧ (𝑑 = ∅ ∨ (lastS‘𝑑) < 𝑥)) ∧ ∀𝑖 ∈ (0..^((♯‘𝑑) − 1))(𝑑‘𝑖) < (lastS‘𝑑)) → ∀𝑗 ∈ (0..^((♯‘(𝑑 ++ ⟨“𝑥”⟩)) − 1))((𝑑 ++ ⟨“𝑥”⟩)‘𝑗) < (lastS‘(𝑑 ++ ⟨“𝑥”⟩)))
179	9, 16, 27, 34, 35, 56, 178	chnind 18544	. 2 ⊢ (𝜑 → ∀𝑖 ∈ (0..^((♯‘𝐶) − 1))(𝐶‘𝑖) < (lastS‘𝐶))
180		chnub.3	. 2 ⊢ (𝜑 → 𝐼 ∈ (0..^((♯‘𝐶) − 1)))
181	2, 179, 180	rspcdva 3577	1 ⊢ (𝜑 → (𝐶‘𝐼) < (lastS‘𝐶))

Colors of variables: wff setvar class

Syntax hints: → wi 4 ↔ wb 206 ∧ wa 395 ∨ wo 847 ∧ w3a 1086 = wceq 1541 ∈ wcel 2113 ≠ wne 2932 ∀wral 3051 ∪ cun 3899 ⊆ wss 3901 ∅c0 4285 {csn 4580 class class class wbr 5098 Po wpo 5530 ‘cfv 6492 (class class class)co 7358 0cc0 11026 1c1 11027 + caddc 11029 ≤ cle 11167 − cmin 11364 -cneg 11365 ℕcn 12145 ℕ₀cn0 12401 ℤcz 12488 ℤ_≥cuz 12751 ..^cfzo 13570 ♯chash 14253 Word cword 14436 lastSclsw 14485 ++ cconcat 14493 ⟨“cs1 14519 Chain cchn 18528

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-10 2146 ax-11 2162 ax-12 2184 ax-ext 2708 ax-rep 5224 ax-sep 5241 ax-nul 5251 ax-pow 5310 ax-pr 5377 ax-un 7680 ax-cnex 11082 ax-resscn 11083 ax-1cn 11084 ax-icn 11085 ax-addcl 11086 ax-addrcl 11087 ax-mulcl 11088 ax-mulrcl 11089 ax-mulcom 11090 ax-addass 11091 ax-mulass 11092 ax-distr 11093 ax-i2m1 11094 ax-1ne0 11095 ax-1rid 11096 ax-rnegex 11097 ax-rrecex 11098 ax-cnre 11099 ax-pre-lttri 11100 ax-pre-lttrn 11101 ax-pre-ltadd 11102 ax-pre-mulgt0 11103

This theorem depends on definitions: df-bi 207 df-an 396 df-or 848 df-3or 1087 df-3an 1088 df-tru 1544 df-fal 1554 df-ex 1781 df-nf 1785 df-sb 2068 df-mo 2539 df-eu 2569 df-clab 2715 df-cleq 2728 df-clel 2811 df-nfc 2885 df-ne 2933 df-nel 3037 df-ral 3052 df-rex 3061 df-reu 3351 df-rab 3400 df-v 3442 df-sbc 3741 df-csb 3850 df-dif 3904 df-un 3906 df-in 3908 df-ss 3918 df-pss 3921 df-nul 4286 df-if 4480 df-pw 4556 df-sn 4581 df-pr 4583 df-op 4587 df-uni 4864 df-int 4903 df-iun 4948 df-br 5099 df-opab 5161 df-mpt 5180 df-tr 5206 df-id 5519 df-eprel 5524 df-po 5532 df-so 5533 df-fr 5577 df-we 5579 df-xp 5630 df-rel 5631 df-cnv 5632 df-co 5633 df-dm 5634 df-rn 5635 df-res 5636 df-ima 5637 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-riota 7315 df-ov 7361 df-oprab 7362 df-mpo 7363 df-om 7809 df-1st 7933 df-2nd 7934 df-frecs 8223 df-wrecs 8254 df-recs 8303 df-rdg 8341 df-1o 8397 df-er 8635 df-en 8884 df-dom 8885 df-sdom 8886 df-fin 8887 df-card 9851 df-pnf 11168 df-mnf 11169 df-xr 11170 df-ltxr 11171 df-le 11172 df-sub 11366 df-neg 11367 df-nn 12146 df-n0 12402 df-xnn0 12475 df-z 12489 df-uz 12752 df-rp 12906 df-fz 13424 df-fzo 13571 df-hash 14254 df-word 14437 df-lsw 14486 df-concat 14494 df-s1 14520 df-substr 14565 df-pfx 14595 df-chn 18529

This theorem is referenced by: chnlt 18546

W3C validator