Theorem rnmptbdlem

Description: Boundness above of the range of a function in maps-to notation. (Contributed by Glauco Siliprandi, 23-Oct-2021)

	Ref	Expression
Hypotheses	rnmptbdlem.x	⊢ Ⅎ 𝑥 𝜑
	rnmptbdlem.y	⊢ Ⅎ 𝑦 𝜑
	rnmptbdlem.b	⊢ ( ( 𝜑 ∧ 𝑥 ∈ 𝐴 ) → 𝐵 ∈ 𝑉 )
Assertion	rnmptbdlem	⊢ ( 𝜑 → ( ∃ 𝑦 ∈ ℝ ∀ 𝑥 ∈ 𝐴 𝐵 ≤ 𝑦 ↔ ∃ 𝑦 ∈ ℝ ∀ 𝑧 ∈ ran ( 𝑥 ∈ 𝐴 ↦ 𝐵 ) 𝑧 ≤ 𝑦 ) )

Proof

Step	Hyp	Ref	Expression
1		rnmptbdlem.x	⊢ Ⅎ 𝑥 𝜑
2		rnmptbdlem.y	⊢ Ⅎ 𝑦 𝜑
3		rnmptbdlem.b	⊢ ( ( 𝜑 ∧ 𝑥 ∈ 𝐴 ) → 𝐵 ∈ 𝑉 )
4		nfcv	⊢ Ⅎ 𝑥 ℝ
5		nfra1	⊢ Ⅎ 𝑥 ∀ 𝑥 ∈ 𝐴 𝐵 ≤ 𝑦
6	4 5	nfrexw	⊢ Ⅎ 𝑥 ∃ 𝑦 ∈ ℝ ∀ 𝑥 ∈ 𝐴 𝐵 ≤ 𝑦
7	1 6	nfan	⊢ Ⅎ 𝑥 ( 𝜑 ∧ ∃ 𝑦 ∈ ℝ ∀ 𝑥 ∈ 𝐴 𝐵 ≤ 𝑦 )
8		simpr	⊢ ( ( 𝜑 ∧ ∃ 𝑦 ∈ ℝ ∀ 𝑥 ∈ 𝐴 𝐵 ≤ 𝑦 ) → ∃ 𝑦 ∈ ℝ ∀ 𝑥 ∈ 𝐴 𝐵 ≤ 𝑦 )
9	7 8	rnmptbdd	⊢ ( ( 𝜑 ∧ ∃ 𝑦 ∈ ℝ ∀ 𝑥 ∈ 𝐴 𝐵 ≤ 𝑦 ) → ∃ 𝑦 ∈ ℝ ∀ 𝑧 ∈ ran ( 𝑥 ∈ 𝐴 ↦ 𝐵 ) 𝑧 ≤ 𝑦 )
10	9	ex	⊢ ( 𝜑 → ( ∃ 𝑦 ∈ ℝ ∀ 𝑥 ∈ 𝐴 𝐵 ≤ 𝑦 → ∃ 𝑦 ∈ ℝ ∀ 𝑧 ∈ ran ( 𝑥 ∈ 𝐴 ↦ 𝐵 ) 𝑧 ≤ 𝑦 ) )
11		nfmpt1	⊢ Ⅎ 𝑥 ( 𝑥 ∈ 𝐴 ↦ 𝐵 )
12	11	nfrn	⊢ Ⅎ 𝑥 ran ( 𝑥 ∈ 𝐴 ↦ 𝐵 )
13		nfv	⊢ Ⅎ 𝑥 𝑧 ≤ 𝑦
14	12 13	nfralw	⊢ Ⅎ 𝑥 ∀ 𝑧 ∈ ran ( 𝑥 ∈ 𝐴 ↦ 𝐵 ) 𝑧 ≤ 𝑦
15	1 14	nfan	⊢ Ⅎ 𝑥 ( 𝜑 ∧ ∀ 𝑧 ∈ ran ( 𝑥 ∈ 𝐴 ↦ 𝐵 ) 𝑧 ≤ 𝑦 )
16		breq1	⊢ ( 𝑧 = 𝐵 → ( 𝑧 ≤ 𝑦 ↔ 𝐵 ≤ 𝑦 ) )
17		simplr	⊢ ( ( ( 𝜑 ∧ ∀ 𝑧 ∈ ran ( 𝑥 ∈ 𝐴 ↦ 𝐵 ) 𝑧 ≤ 𝑦 ) ∧ 𝑥 ∈ 𝐴 ) → ∀ 𝑧 ∈ ran ( 𝑥 ∈ 𝐴 ↦ 𝐵 ) 𝑧 ≤ 𝑦 )
18		eqid	⊢ ( 𝑥 ∈ 𝐴 ↦ 𝐵 ) = ( 𝑥 ∈ 𝐴 ↦ 𝐵 )
19		simpr	⊢ ( ( ( 𝜑 ∧ ∀ 𝑧 ∈ ran ( 𝑥 ∈ 𝐴 ↦ 𝐵 ) 𝑧 ≤ 𝑦 ) ∧ 𝑥 ∈ 𝐴 ) → 𝑥 ∈ 𝐴 )
20	3	adantlr	⊢ ( ( ( 𝜑 ∧ ∀ 𝑧 ∈ ran ( 𝑥 ∈ 𝐴 ↦ 𝐵 ) 𝑧 ≤ 𝑦 ) ∧ 𝑥 ∈ 𝐴 ) → 𝐵 ∈ 𝑉 )
21	18 19 20	elrnmpt1d	⊢ ( ( ( 𝜑 ∧ ∀ 𝑧 ∈ ran ( 𝑥 ∈ 𝐴 ↦ 𝐵 ) 𝑧 ≤ 𝑦 ) ∧ 𝑥 ∈ 𝐴 ) → 𝐵 ∈ ran ( 𝑥 ∈ 𝐴 ↦ 𝐵 ) )
22	16 17 21	rspcdva	⊢ ( ( ( 𝜑 ∧ ∀ 𝑧 ∈ ran ( 𝑥 ∈ 𝐴 ↦ 𝐵 ) 𝑧 ≤ 𝑦 ) ∧ 𝑥 ∈ 𝐴 ) → 𝐵 ≤ 𝑦 )
23	15 22	ralrimia	⊢ ( ( 𝜑 ∧ ∀ 𝑧 ∈ ran ( 𝑥 ∈ 𝐴 ↦ 𝐵 ) 𝑧 ≤ 𝑦 ) → ∀ 𝑥 ∈ 𝐴 𝐵 ≤ 𝑦 )
24	23	ex	⊢ ( 𝜑 → ( ∀ 𝑧 ∈ ran ( 𝑥 ∈ 𝐴 ↦ 𝐵 ) 𝑧 ≤ 𝑦 → ∀ 𝑥 ∈ 𝐴 𝐵 ≤ 𝑦 ) )
25	24	a1d	⊢ ( 𝜑 → ( 𝑦 ∈ ℝ → ( ∀ 𝑧 ∈ ran ( 𝑥 ∈ 𝐴 ↦ 𝐵 ) 𝑧 ≤ 𝑦 → ∀ 𝑥 ∈ 𝐴 𝐵 ≤ 𝑦 ) ) )
26	2 25	reximdai	⊢ ( 𝜑 → ( ∃ 𝑦 ∈ ℝ ∀ 𝑧 ∈ ran ( 𝑥 ∈ 𝐴 ↦ 𝐵 ) 𝑧 ≤ 𝑦 → ∃ 𝑦 ∈ ℝ ∀ 𝑥 ∈ 𝐴 𝐵 ≤ 𝑦 ) )
27	10 26	impbid	⊢ ( 𝜑 → ( ∃ 𝑦 ∈ ℝ ∀ 𝑥 ∈ 𝐴 𝐵 ≤ 𝑦 ↔ ∃ 𝑦 ∈ ℝ ∀ 𝑧 ∈ ran ( 𝑥 ∈ 𝐴 ↦ 𝐵 ) 𝑧 ≤ 𝑦 ) )