infrpge - Mathbox for Glauco Siliprandi

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Theorem infrpge 43834

Description: The infimum of a nonempty, bounded subset of extended reals can be approximated from above by an element of the set. (Contributed by Glauco Siliprandi, 11-Oct-2020.)

**Hypotheses**
Ref	Expression
infrpge.xph	⊢ Ⅎ𝑥𝜑
infrpge.a	⊢ (𝜑 → 𝐴 ⊆ ℝ^*)
infrpge.an0	⊢ (𝜑 → 𝐴 ≠ ∅)
infrpge.bnd	⊢ (𝜑 → ∃𝑥 ∈ ℝ ∀𝑦 ∈ 𝐴 𝑥 ≤ 𝑦)
infrpge.b	⊢ (𝜑 → 𝐵 ∈ ℝ⁺)

**Assertion**
Ref	Expression
infrpge	⊢ (𝜑 → ∃𝑧 ∈ 𝐴 𝑧 ≤ (inf(𝐴, ℝ^*, < ) +_𝑒 𝐵))

Distinct variable groups: 𝑥,𝐴,𝑦 𝑧,𝐴 𝑧,𝐵 𝜑,𝑧 Allowed substitution hints: 𝜑(𝑥,𝑦) 𝐵(𝑥,𝑦)

**Proof of Theorem infrpge**
Step	Hyp	Ref	Expression
1		infrpge.an0	. . . . . 6 ⊢ (𝜑 → 𝐴 ≠ ∅)
2		n0 4342	. . . . . . 7 ⊢ (𝐴 ≠ ∅ ↔ ∃𝑧 𝑧 ∈ 𝐴)
3	2	biimpi 215	. . . . . 6 ⊢ (𝐴 ≠ ∅ → ∃𝑧 𝑧 ∈ 𝐴)
4	1, 3	syl 17	. . . . 5 ⊢ (𝜑 → ∃𝑧 𝑧 ∈ 𝐴)
5	4	adantr 481	. . . 4 ⊢ ((𝜑 ∧ inf(𝐴, ℝ^*, < ) = +∞) → ∃𝑧 𝑧 ∈ 𝐴)
6		nfv 1917	. . . . 5 ⊢ Ⅎ𝑧(𝜑 ∧ inf(𝐴, ℝ^*, < ) = +∞)
7		simpr 485	. . . . . . 7 ⊢ (((𝜑 ∧ inf(𝐴, ℝ^*, < ) = +∞) ∧ 𝑧 ∈ 𝐴) → 𝑧 ∈ 𝐴)
8		infrpge.a	. . . . . . . . . . . 12 ⊢ (𝜑 → 𝐴 ⊆ ℝ^*)
9	8	adantr 481	. . . . . . . . . . 11 ⊢ ((𝜑 ∧ 𝑧 ∈ 𝐴) → 𝐴 ⊆ ℝ^*)
10		simpr 485	. . . . . . . . . . 11 ⊢ ((𝜑 ∧ 𝑧 ∈ 𝐴) → 𝑧 ∈ 𝐴)
11	9, 10	sseldd 3979	. . . . . . . . . 10 ⊢ ((𝜑 ∧ 𝑧 ∈ 𝐴) → 𝑧 ∈ ℝ^*)
12		pnfge 13092	. . . . . . . . . 10 ⊢ (𝑧 ∈ ℝ^* → 𝑧 ≤ +∞)
13	11, 12	syl 17	. . . . . . . . 9 ⊢ ((𝜑 ∧ 𝑧 ∈ 𝐴) → 𝑧 ≤ +∞)
14	13	adantlr 713	. . . . . . . 8 ⊢ (((𝜑 ∧ inf(𝐴, ℝ^*, < ) = +∞) ∧ 𝑧 ∈ 𝐴) → 𝑧 ≤ +∞)
15		oveq1 7400	. . . . . . . . . . 11 ⊢ (inf(𝐴, ℝ^, < ) = +∞ → (inf(𝐴, ℝ^, < ) +_𝑒 𝐵) = (+∞ +_𝑒 𝐵))
16	15	adantl 482	. . . . . . . . . 10 ⊢ ((𝜑 ∧ inf(𝐴, ℝ^, < ) = +∞) → (inf(𝐴, ℝ^, < ) +_𝑒 𝐵) = (+∞ +_𝑒 𝐵))
17		infrpge.b	. . . . . . . . . . . . 13 ⊢ (𝜑 → 𝐵 ∈ ℝ⁺)
18	17	rpxrd 12999	. . . . . . . . . . . 12 ⊢ (𝜑 → 𝐵 ∈ ℝ^*)
19	17	rpred 12998	. . . . . . . . . . . . 13 ⊢ (𝜑 → 𝐵 ∈ ℝ)
20		renemnf 11245	. . . . . . . . . . . . 13 ⊢ (𝐵 ∈ ℝ → 𝐵 ≠ -∞)
21	19, 20	syl 17	. . . . . . . . . . . 12 ⊢ (𝜑 → 𝐵 ≠ -∞)
22		xaddpnf2 13188	. . . . . . . . . . . 12 ⊢ ((𝐵 ∈ ℝ^* ∧ 𝐵 ≠ -∞) → (+∞ +_𝑒 𝐵) = +∞)
23	18, 21, 22	syl2anc 584	. . . . . . . . . . 11 ⊢ (𝜑 → (+∞ +_𝑒 𝐵) = +∞)
24	23	adantr 481	. . . . . . . . . 10 ⊢ ((𝜑 ∧ inf(𝐴, ℝ^*, < ) = +∞) → (+∞ +_𝑒 𝐵) = +∞)
25	16, 24	eqtr2d 2772	. . . . . . . . 9 ⊢ ((𝜑 ∧ inf(𝐴, ℝ^, < ) = +∞) → +∞ = (inf(𝐴, ℝ^, < ) +_𝑒 𝐵))
26	25	adantr 481	. . . . . . . 8 ⊢ (((𝜑 ∧ inf(𝐴, ℝ^, < ) = +∞) ∧ 𝑧 ∈ 𝐴) → +∞ = (inf(𝐴, ℝ^, < ) +_𝑒 𝐵))
27	14, 26	breqtrd 5167	. . . . . . 7 ⊢ (((𝜑 ∧ inf(𝐴, ℝ^, < ) = +∞) ∧ 𝑧 ∈ 𝐴) → 𝑧 ≤ (inf(𝐴, ℝ^, < ) +_𝑒 𝐵))
28	7, 27	jca 512	. . . . . 6 ⊢ (((𝜑 ∧ inf(𝐴, ℝ^, < ) = +∞) ∧ 𝑧 ∈ 𝐴) → (𝑧 ∈ 𝐴 ∧ 𝑧 ≤ (inf(𝐴, ℝ^, < ) +_𝑒 𝐵)))
29	28	ex 413	. . . . 5 ⊢ ((𝜑 ∧ inf(𝐴, ℝ^, < ) = +∞) → (𝑧 ∈ 𝐴 → (𝑧 ∈ 𝐴 ∧ 𝑧 ≤ (inf(𝐴, ℝ^, < ) +_𝑒 𝐵))))
30	6, 29	eximd 2209	. . . 4 ⊢ ((𝜑 ∧ inf(𝐴, ℝ^, < ) = +∞) → (∃𝑧 𝑧 ∈ 𝐴 → ∃𝑧(𝑧 ∈ 𝐴 ∧ 𝑧 ≤ (inf(𝐴, ℝ^, < ) +_𝑒 𝐵))))
31	5, 30	mpd 15	. . 3 ⊢ ((𝜑 ∧ inf(𝐴, ℝ^, < ) = +∞) → ∃𝑧(𝑧 ∈ 𝐴 ∧ 𝑧 ≤ (inf(𝐴, ℝ^, < ) +_𝑒 𝐵)))
32		df-rex 3070	. . 3 ⊢ (∃𝑧 ∈ 𝐴 𝑧 ≤ (inf(𝐴, ℝ^, < ) +_𝑒 𝐵) ↔ ∃𝑧(𝑧 ∈ 𝐴 ∧ 𝑧 ≤ (inf(𝐴, ℝ^, < ) +_𝑒 𝐵)))
33	31, 32	sylibr 233	. 2 ⊢ ((𝜑 ∧ inf(𝐴, ℝ^, < ) = +∞) → ∃𝑧 ∈ 𝐴 𝑧 ≤ (inf(𝐴, ℝ^, < ) +_𝑒 𝐵))
34		simpl 483	. . . 4 ⊢ ((𝜑 ∧ ¬ inf(𝐴, ℝ^*, < ) = +∞) → 𝜑)
35		infrpge.bnd	. . . . . . . . 9 ⊢ (𝜑 → ∃𝑥 ∈ ℝ ∀𝑦 ∈ 𝐴 𝑥 ≤ 𝑦)
36		infrpge.xph	. . . . . . . . . 10 ⊢ Ⅎ𝑥𝜑
37		nfv 1917	. . . . . . . . . 10 ⊢ Ⅎ𝑥-∞ < inf(𝐴, ℝ^*, < )
38		mnfxr 11253	. . . . . . . . . . . . 13 ⊢ -∞ ∈ ℝ^*
39	38	a1i 11	. . . . . . . . . . . 12 ⊢ ((𝜑 ∧ 𝑥 ∈ ℝ ∧ ∀𝑦 ∈ 𝐴 𝑥 ≤ 𝑦) → -∞ ∈ ℝ^*)
40		rexr 11242	. . . . . . . . . . . . 13 ⊢ (𝑥 ∈ ℝ → 𝑥 ∈ ℝ^*)
41	40	3ad2ant2 1134	. . . . . . . . . . . 12 ⊢ ((𝜑 ∧ 𝑥 ∈ ℝ ∧ ∀𝑦 ∈ 𝐴 𝑥 ≤ 𝑦) → 𝑥 ∈ ℝ^*)
42		infxrcl 13294	. . . . . . . . . . . . . 14 ⊢ (𝐴 ⊆ ℝ^* → inf(𝐴, ℝ^, < ) ∈ ℝ^)
43	8, 42	syl 17	. . . . . . . . . . . . 13 ⊢ (𝜑 → inf(𝐴, ℝ^, < ) ∈ ℝ^)
44	43	3ad2ant1 1133	. . . . . . . . . . . 12 ⊢ ((𝜑 ∧ 𝑥 ∈ ℝ ∧ ∀𝑦 ∈ 𝐴 𝑥 ≤ 𝑦) → inf(𝐴, ℝ^, < ) ∈ ℝ^)
45		mnflt 13085	. . . . . . . . . . . . 13 ⊢ (𝑥 ∈ ℝ → -∞ < 𝑥)
46	45	3ad2ant2 1134	. . . . . . . . . . . 12 ⊢ ((𝜑 ∧ 𝑥 ∈ ℝ ∧ ∀𝑦 ∈ 𝐴 𝑥 ≤ 𝑦) → -∞ < 𝑥)
47		simp3 1138	. . . . . . . . . . . . 13 ⊢ ((𝜑 ∧ 𝑥 ∈ ℝ ∧ ∀𝑦 ∈ 𝐴 𝑥 ≤ 𝑦) → ∀𝑦 ∈ 𝐴 𝑥 ≤ 𝑦)
48	8	adantr 481	. . . . . . . . . . . . . . 15 ⊢ ((𝜑 ∧ 𝑥 ∈ ℝ) → 𝐴 ⊆ ℝ^*)
49	40	adantl 482	. . . . . . . . . . . . . . 15 ⊢ ((𝜑 ∧ 𝑥 ∈ ℝ) → 𝑥 ∈ ℝ^*)
50		infxrgelb 13296	. . . . . . . . . . . . . . 15 ⊢ ((𝐴 ⊆ ℝ^* ∧ 𝑥 ∈ ℝ^) → (𝑥 ≤ inf(𝐴, ℝ^, < ) ↔ ∀𝑦 ∈ 𝐴 𝑥 ≤ 𝑦))
51	48, 49, 50	syl2anc 584	. . . . . . . . . . . . . 14 ⊢ ((𝜑 ∧ 𝑥 ∈ ℝ) → (𝑥 ≤ inf(𝐴, ℝ^*, < ) ↔ ∀𝑦 ∈ 𝐴 𝑥 ≤ 𝑦))
52	51	3adant3 1132	. . . . . . . . . . . . 13 ⊢ ((𝜑 ∧ 𝑥 ∈ ℝ ∧ ∀𝑦 ∈ 𝐴 𝑥 ≤ 𝑦) → (𝑥 ≤ inf(𝐴, ℝ^*, < ) ↔ ∀𝑦 ∈ 𝐴 𝑥 ≤ 𝑦))
53	47, 52	mpbird 256	. . . . . . . . . . . 12 ⊢ ((𝜑 ∧ 𝑥 ∈ ℝ ∧ ∀𝑦 ∈ 𝐴 𝑥 ≤ 𝑦) → 𝑥 ≤ inf(𝐴, ℝ^*, < ))
54	39, 41, 44, 46, 53	xrltletrd 13122	. . . . . . . . . . 11 ⊢ ((𝜑 ∧ 𝑥 ∈ ℝ ∧ ∀𝑦 ∈ 𝐴 𝑥 ≤ 𝑦) → -∞ < inf(𝐴, ℝ^*, < ))
55	54	3exp 1119	. . . . . . . . . 10 ⊢ (𝜑 → (𝑥 ∈ ℝ → (∀𝑦 ∈ 𝐴 𝑥 ≤ 𝑦 → -∞ < inf(𝐴, ℝ^*, < ))))
56	36, 37, 55	rexlimd 3262	. . . . . . . . 9 ⊢ (𝜑 → (∃𝑥 ∈ ℝ ∀𝑦 ∈ 𝐴 𝑥 ≤ 𝑦 → -∞ < inf(𝐴, ℝ^*, < )))
57	35, 56	mpd 15	. . . . . . . 8 ⊢ (𝜑 → -∞ < inf(𝐴, ℝ^*, < ))
58	57	adantr 481	. . . . . . 7 ⊢ ((𝜑 ∧ ¬ inf(𝐴, ℝ^, < ) = +∞) → -∞ < inf(𝐴, ℝ^, < ))
59		neqne 2947	. . . . . . . . 9 ⊢ (¬ inf(𝐴, ℝ^, < ) = +∞ → inf(𝐴, ℝ^, < ) ≠ +∞)
60	59	adantl 482	. . . . . . . 8 ⊢ ((𝜑 ∧ ¬ inf(𝐴, ℝ^, < ) = +∞) → inf(𝐴, ℝ^, < ) ≠ +∞)
61	43	adantr 481	. . . . . . . 8 ⊢ ((𝜑 ∧ ¬ inf(𝐴, ℝ^, < ) = +∞) → inf(𝐴, ℝ^, < ) ∈ ℝ^*)
62	60, 61	nepnfltpnf 43825	. . . . . . 7 ⊢ ((𝜑 ∧ ¬ inf(𝐴, ℝ^, < ) = +∞) → inf(𝐴, ℝ^, < ) < +∞)
63	58, 62	jca 512	. . . . . 6 ⊢ ((𝜑 ∧ ¬ inf(𝐴, ℝ^, < ) = +∞) → (-∞ < inf(𝐴, ℝ^, < ) ∧ inf(𝐴, ℝ^*, < ) < +∞))
64		xrrebnd 13129	. . . . . . . 8 ⊢ (inf(𝐴, ℝ^, < ) ∈ ℝ^ → (inf(𝐴, ℝ^, < ) ∈ ℝ ↔ (-∞ < inf(𝐴, ℝ^, < ) ∧ inf(𝐴, ℝ^*, < ) < +∞)))
65	43, 64	syl 17	. . . . . . 7 ⊢ (𝜑 → (inf(𝐴, ℝ^, < ) ∈ ℝ ↔ (-∞ < inf(𝐴, ℝ^, < ) ∧ inf(𝐴, ℝ^*, < ) < +∞)))
66	65	adantr 481	. . . . . 6 ⊢ ((𝜑 ∧ ¬ inf(𝐴, ℝ^, < ) = +∞) → (inf(𝐴, ℝ^, < ) ∈ ℝ ↔ (-∞ < inf(𝐴, ℝ^, < ) ∧ inf(𝐴, ℝ^, < ) < +∞)))
67	63, 66	mpbird 256	. . . . 5 ⊢ ((𝜑 ∧ ¬ inf(𝐴, ℝ^, < ) = +∞) → inf(𝐴, ℝ^, < ) ∈ ℝ)
68		simpr 485	. . . . . . . 8 ⊢ ((𝜑 ∧ inf(𝐴, ℝ^, < ) ∈ ℝ) → inf(𝐴, ℝ^, < ) ∈ ℝ)
69	17	adantr 481	. . . . . . . 8 ⊢ ((𝜑 ∧ inf(𝐴, ℝ^*, < ) ∈ ℝ) → 𝐵 ∈ ℝ⁺)
70	68, 69	ltaddrpd 13031	. . . . . . 7 ⊢ ((𝜑 ∧ inf(𝐴, ℝ^, < ) ∈ ℝ) → inf(𝐴, ℝ^, < ) < (inf(𝐴, ℝ^*, < ) + 𝐵))
71	19	adantr 481	. . . . . . . . 9 ⊢ ((𝜑 ∧ inf(𝐴, ℝ^*, < ) ∈ ℝ) → 𝐵 ∈ ℝ)
72		rexadd 13193	. . . . . . . . 9 ⊢ ((inf(𝐴, ℝ^, < ) ∈ ℝ ∧ 𝐵 ∈ ℝ) → (inf(𝐴, ℝ^, < ) +_𝑒 𝐵) = (inf(𝐴, ℝ^*, < ) + 𝐵))
73	68, 71, 72	syl2anc 584	. . . . . . . 8 ⊢ ((𝜑 ∧ inf(𝐴, ℝ^, < ) ∈ ℝ) → (inf(𝐴, ℝ^, < ) +_𝑒 𝐵) = (inf(𝐴, ℝ^*, < ) + 𝐵))
74	73	eqcomd 2737	. . . . . . 7 ⊢ ((𝜑 ∧ inf(𝐴, ℝ^, < ) ∈ ℝ) → (inf(𝐴, ℝ^, < ) + 𝐵) = (inf(𝐴, ℝ^*, < ) +_𝑒 𝐵))
75	70, 74	breqtrd 5167	. . . . . 6 ⊢ ((𝜑 ∧ inf(𝐴, ℝ^, < ) ∈ ℝ) → inf(𝐴, ℝ^, < ) < (inf(𝐴, ℝ^*, < ) +_𝑒 𝐵))
76	43	adantr 481	. . . . . . 7 ⊢ ((𝜑 ∧ inf(𝐴, ℝ^, < ) ∈ ℝ) → inf(𝐴, ℝ^, < ) ∈ ℝ^*)
77	43, 18	xaddcld 13262	. . . . . . . 8 ⊢ (𝜑 → (inf(𝐴, ℝ^, < ) +_𝑒 𝐵) ∈ ℝ^)
78	77	adantr 481	. . . . . . 7 ⊢ ((𝜑 ∧ inf(𝐴, ℝ^, < ) ∈ ℝ) → (inf(𝐴, ℝ^, < ) +_𝑒 𝐵) ∈ ℝ^*)
79		xrltnle 11263	. . . . . . 7 ⊢ ((inf(𝐴, ℝ^, < ) ∈ ℝ^ ∧ (inf(𝐴, ℝ^, < ) +_𝑒 𝐵) ∈ ℝ^) → (inf(𝐴, ℝ^, < ) < (inf(𝐴, ℝ^, < ) +_𝑒 𝐵) ↔ ¬ (inf(𝐴, ℝ^, < ) +_𝑒 𝐵) ≤ inf(𝐴, ℝ^, < )))
80	76, 78, 79	syl2anc 584	. . . . . 6 ⊢ ((𝜑 ∧ inf(𝐴, ℝ^, < ) ∈ ℝ) → (inf(𝐴, ℝ^, < ) < (inf(𝐴, ℝ^, < ) +_𝑒 𝐵) ↔ ¬ (inf(𝐴, ℝ^, < ) +_𝑒 𝐵) ≤ inf(𝐴, ℝ^*, < )))
81	75, 80	mpbid 231	. . . . 5 ⊢ ((𝜑 ∧ inf(𝐴, ℝ^, < ) ∈ ℝ) → ¬ (inf(𝐴, ℝ^, < ) +_𝑒 𝐵) ≤ inf(𝐴, ℝ^*, < ))
82	34, 67, 81	syl2anc 584	. . . 4 ⊢ ((𝜑 ∧ ¬ inf(𝐴, ℝ^, < ) = +∞) → ¬ (inf(𝐴, ℝ^, < ) +_𝑒 𝐵) ≤ inf(𝐴, ℝ^*, < ))
83		simpr 485	. . . . . 6 ⊢ ((𝜑 ∧ ¬ (inf(𝐴, ℝ^, < ) +_𝑒 𝐵) ≤ inf(𝐴, ℝ^, < )) → ¬ (inf(𝐴, ℝ^, < ) +_𝑒 𝐵) ≤ inf(𝐴, ℝ^, < ))
84		simpl 483	. . . . . . 7 ⊢ ((𝜑 ∧ ¬ (inf(𝐴, ℝ^, < ) +_𝑒 𝐵) ≤ inf(𝐴, ℝ^, < )) → 𝜑)
85		infxrgelb 13296	. . . . . . . 8 ⊢ ((𝐴 ⊆ ℝ^* ∧ (inf(𝐴, ℝ^, < ) +_𝑒 𝐵) ∈ ℝ^) → ((inf(𝐴, ℝ^, < ) +_𝑒 𝐵) ≤ inf(𝐴, ℝ^, < ) ↔ ∀𝑧 ∈ 𝐴 (inf(𝐴, ℝ^*, < ) +_𝑒 𝐵) ≤ 𝑧))
86	8, 77, 85	syl2anc 584	. . . . . . 7 ⊢ (𝜑 → ((inf(𝐴, ℝ^, < ) +_𝑒 𝐵) ≤ inf(𝐴, ℝ^, < ) ↔ ∀𝑧 ∈ 𝐴 (inf(𝐴, ℝ^*, < ) +_𝑒 𝐵) ≤ 𝑧))
87	84, 86	syl 17	. . . . . 6 ⊢ ((𝜑 ∧ ¬ (inf(𝐴, ℝ^, < ) +_𝑒 𝐵) ≤ inf(𝐴, ℝ^, < )) → ((inf(𝐴, ℝ^, < ) +_𝑒 𝐵) ≤ inf(𝐴, ℝ^, < ) ↔ ∀𝑧 ∈ 𝐴 (inf(𝐴, ℝ^*, < ) +_𝑒 𝐵) ≤ 𝑧))
88	83, 87	mtbid 323	. . . . 5 ⊢ ((𝜑 ∧ ¬ (inf(𝐴, ℝ^, < ) +_𝑒 𝐵) ≤ inf(𝐴, ℝ^, < )) → ¬ ∀𝑧 ∈ 𝐴 (inf(𝐴, ℝ^*, < ) +_𝑒 𝐵) ≤ 𝑧)
89		rexnal 3099	. . . . 5 ⊢ (∃𝑧 ∈ 𝐴 ¬ (inf(𝐴, ℝ^, < ) +_𝑒 𝐵) ≤ 𝑧 ↔ ¬ ∀𝑧 ∈ 𝐴 (inf(𝐴, ℝ^, < ) +_𝑒 𝐵) ≤ 𝑧)
90	88, 89	sylibr 233	. . . 4 ⊢ ((𝜑 ∧ ¬ (inf(𝐴, ℝ^, < ) +_𝑒 𝐵) ≤ inf(𝐴, ℝ^, < )) → ∃𝑧 ∈ 𝐴 ¬ (inf(𝐴, ℝ^*, < ) +_𝑒 𝐵) ≤ 𝑧)
91	34, 82, 90	syl2anc 584	. . 3 ⊢ ((𝜑 ∧ ¬ inf(𝐴, ℝ^, < ) = +∞) → ∃𝑧 ∈ 𝐴 ¬ (inf(𝐴, ℝ^, < ) +_𝑒 𝐵) ≤ 𝑧)
92	11	adantr 481	. . . . . . 7 ⊢ (((𝜑 ∧ 𝑧 ∈ 𝐴) ∧ ¬ (inf(𝐴, ℝ^, < ) +_𝑒 𝐵) ≤ 𝑧) → 𝑧 ∈ ℝ^)
93	77	ad2antrr 724	. . . . . . 7 ⊢ (((𝜑 ∧ 𝑧 ∈ 𝐴) ∧ ¬ (inf(𝐴, ℝ^, < ) +_𝑒 𝐵) ≤ 𝑧) → (inf(𝐴, ℝ^, < ) +_𝑒 𝐵) ∈ ℝ^*)
94		simpr 485	. . . . . . . 8 ⊢ (((𝜑 ∧ 𝑧 ∈ 𝐴) ∧ ¬ (inf(𝐴, ℝ^, < ) +_𝑒 𝐵) ≤ 𝑧) → ¬ (inf(𝐴, ℝ^, < ) +_𝑒 𝐵) ≤ 𝑧)
95		xrltnle 11263	. . . . . . . . 9 ⊢ ((𝑧 ∈ ℝ^* ∧ (inf(𝐴, ℝ^, < ) +_𝑒 𝐵) ∈ ℝ^) → (𝑧 < (inf(𝐴, ℝ^, < ) +_𝑒 𝐵) ↔ ¬ (inf(𝐴, ℝ^, < ) +_𝑒 𝐵) ≤ 𝑧))
96	92, 93, 95	syl2anc 584	. . . . . . . 8 ⊢ (((𝜑 ∧ 𝑧 ∈ 𝐴) ∧ ¬ (inf(𝐴, ℝ^, < ) +_𝑒 𝐵) ≤ 𝑧) → (𝑧 < (inf(𝐴, ℝ^, < ) +_𝑒 𝐵) ↔ ¬ (inf(𝐴, ℝ^*, < ) +_𝑒 𝐵) ≤ 𝑧))
97	94, 96	mpbird 256	. . . . . . 7 ⊢ (((𝜑 ∧ 𝑧 ∈ 𝐴) ∧ ¬ (inf(𝐴, ℝ^, < ) +_𝑒 𝐵) ≤ 𝑧) → 𝑧 < (inf(𝐴, ℝ^, < ) +_𝑒 𝐵))
98	92, 93, 97	xrltled 13111	. . . . . 6 ⊢ (((𝜑 ∧ 𝑧 ∈ 𝐴) ∧ ¬ (inf(𝐴, ℝ^, < ) +_𝑒 𝐵) ≤ 𝑧) → 𝑧 ≤ (inf(𝐴, ℝ^, < ) +_𝑒 𝐵))
99	98	ex 413	. . . . 5 ⊢ ((𝜑 ∧ 𝑧 ∈ 𝐴) → (¬ (inf(𝐴, ℝ^, < ) +_𝑒 𝐵) ≤ 𝑧 → 𝑧 ≤ (inf(𝐴, ℝ^, < ) +_𝑒 𝐵)))
100	99	adantlr 713	. . . 4 ⊢ (((𝜑 ∧ ¬ inf(𝐴, ℝ^, < ) = +∞) ∧ 𝑧 ∈ 𝐴) → (¬ (inf(𝐴, ℝ^, < ) +_𝑒 𝐵) ≤ 𝑧 → 𝑧 ≤ (inf(𝐴, ℝ^*, < ) +_𝑒 𝐵)))
101	100	reximdva 3167	. . 3 ⊢ ((𝜑 ∧ ¬ inf(𝐴, ℝ^, < ) = +∞) → (∃𝑧 ∈ 𝐴 ¬ (inf(𝐴, ℝ^, < ) +_𝑒 𝐵) ≤ 𝑧 → ∃𝑧 ∈ 𝐴 𝑧 ≤ (inf(𝐴, ℝ^*, < ) +_𝑒 𝐵)))
102	91, 101	mpd 15	. 2 ⊢ ((𝜑 ∧ ¬ inf(𝐴, ℝ^, < ) = +∞) → ∃𝑧 ∈ 𝐴 𝑧 ≤ (inf(𝐴, ℝ^, < ) +_𝑒 𝐵))
103	33, 102	pm2.61dan 811	1 ⊢ (𝜑 → ∃𝑧 ∈ 𝐴 𝑧 ≤ (inf(𝐴, ℝ^*, < ) +_𝑒 𝐵))

Colors of variables: wff setvar class

Syntax hints: ¬ wn 3 → wi 4 ↔ wb 205 ∧ wa 396 ∧ w3a 1087 = wceq 1541 ∃wex 1781 Ⅎwnf 1785 ∈ wcel 2106 ≠ wne 2939 ∀wral 3060 ∃wrex 3069 ⊆ wss 3944 ∅c0 4318 class class class wbr 5141 (class class class)co 7393 infcinf 9418 ℝcr 11091 + caddc 11095 +∞cpnf 11227 -∞cmnf 11228 ℝ^*cxr 11229 < clt 11230 ≤ cle 11231 ℝ⁺crp 12956 +_𝑒 cxad 13072

This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1797 ax-4 1811 ax-5 1913 ax-6 1971 ax-7 2011 ax-8 2108 ax-9 2116 ax-10 2137 ax-11 2154 ax-12 2171 ax-ext 2702 ax-sep 5292 ax-nul 5299 ax-pow 5356 ax-pr 5420 ax-un 7708 ax-cnex 11148 ax-resscn 11149 ax-1cn 11150 ax-icn 11151 ax-addcl 11152 ax-addrcl 11153 ax-mulcl 11154 ax-mulrcl 11155 ax-mulcom 11156 ax-addass 11157 ax-mulass 11158 ax-distr 11159 ax-i2m1 11160 ax-1ne0 11161 ax-1rid 11162 ax-rnegex 11163 ax-rrecex 11164 ax-cnre 11165 ax-pre-lttri 11166 ax-pre-lttrn 11167 ax-pre-ltadd 11168 ax-pre-mulgt0 11169 ax-pre-sup 11170

This theorem depends on definitions: df-bi 206 df-an 397 df-or 846 df-3or 1088 df-3an 1089 df-tru 1544 df-fal 1554 df-ex 1782 df-nf 1786 df-sb 2068 df-mo 2533 df-eu 2562 df-clab 2709 df-cleq 2723 df-clel 2809 df-nfc 2884 df-ne 2940 df-nel 3046 df-ral 3061 df-rex 3070 df-rmo 3375 df-reu 3376 df-rab 3432 df-v 3475 df-sbc 3774 df-csb 3890 df-dif 3947 df-un 3949 df-in 3951 df-ss 3961 df-nul 4319 df-if 4523 df-pw 4598 df-sn 4623 df-pr 4625 df-op 4629 df-uni 4902 df-iun 4992 df-br 5142 df-opab 5204 df-mpt 5225 df-id 5567 df-po 5581 df-so 5582 df-xp 5675 df-rel 5676 df-cnv 5677 df-co 5678 df-dm 5679 df-rn 5680 df-res 5681 df-ima 5682 df-iota 6484 df-fun 6534 df-fn 6535 df-f 6536 df-f1 6537 df-fo 6538 df-f1o 6539 df-fv 6540 df-riota 7349 df-ov 7396 df-oprab 7397 df-mpo 7398 df-1st 7957 df-2nd 7958 df-er 8686 df-en 8923 df-dom 8924 df-sdom 8925 df-sup 9419 df-inf 9420 df-pnf 11232 df-mnf 11233 df-xr 11234 df-ltxr 11235 df-le 11236 df-sub 11428 df-neg 11429 df-rp 12957 df-xadd 13075

This theorem is referenced by: infleinf 43855 infrpgernmpt 43948 ovnlerp 45051

W3C validator