Metamath Proof Explorer


Theorem elicores

Description: Membership in a left-closed, right-open interval with real bounds. (Contributed by Glauco Siliprandi, 11-Oct-2020)

Ref Expression
Assertion elicores ( 𝐴 ∈ ran ( [,) ↾ ( ℝ × ℝ ) ) ↔ ∃ 𝑥 ∈ ℝ ∃ 𝑦 ∈ ℝ 𝐴 = ( 𝑥 [,) 𝑦 ) )

Proof

Step Hyp Ref Expression
1 df-ico [,) = ( 𝑥 ∈ ℝ* , 𝑦 ∈ ℝ* ↦ { 𝑧 ∈ ℝ* ∣ ( 𝑥𝑧𝑧 < 𝑦 ) } )
2 1 reseq1i ( [,) ↾ ( ℝ × ℝ ) ) = ( ( 𝑥 ∈ ℝ* , 𝑦 ∈ ℝ* ↦ { 𝑧 ∈ ℝ* ∣ ( 𝑥𝑧𝑧 < 𝑦 ) } ) ↾ ( ℝ × ℝ ) )
3 ressxr ℝ ⊆ ℝ*
4 resmpo ( ( ℝ ⊆ ℝ* ∧ ℝ ⊆ ℝ* ) → ( ( 𝑥 ∈ ℝ* , 𝑦 ∈ ℝ* ↦ { 𝑧 ∈ ℝ* ∣ ( 𝑥𝑧𝑧 < 𝑦 ) } ) ↾ ( ℝ × ℝ ) ) = ( 𝑥 ∈ ℝ , 𝑦 ∈ ℝ ↦ { 𝑧 ∈ ℝ* ∣ ( 𝑥𝑧𝑧 < 𝑦 ) } ) )
5 3 3 4 mp2an ( ( 𝑥 ∈ ℝ* , 𝑦 ∈ ℝ* ↦ { 𝑧 ∈ ℝ* ∣ ( 𝑥𝑧𝑧 < 𝑦 ) } ) ↾ ( ℝ × ℝ ) ) = ( 𝑥 ∈ ℝ , 𝑦 ∈ ℝ ↦ { 𝑧 ∈ ℝ* ∣ ( 𝑥𝑧𝑧 < 𝑦 ) } )
6 2 5 eqtri ( [,) ↾ ( ℝ × ℝ ) ) = ( 𝑥 ∈ ℝ , 𝑦 ∈ ℝ ↦ { 𝑧 ∈ ℝ* ∣ ( 𝑥𝑧𝑧 < 𝑦 ) } )
7 6 rneqi ran ( [,) ↾ ( ℝ × ℝ ) ) = ran ( 𝑥 ∈ ℝ , 𝑦 ∈ ℝ ↦ { 𝑧 ∈ ℝ* ∣ ( 𝑥𝑧𝑧 < 𝑦 ) } )
8 7 eleq2i ( 𝐴 ∈ ran ( [,) ↾ ( ℝ × ℝ ) ) ↔ 𝐴 ∈ ran ( 𝑥 ∈ ℝ , 𝑦 ∈ ℝ ↦ { 𝑧 ∈ ℝ* ∣ ( 𝑥𝑧𝑧 < 𝑦 ) } ) )
9 eqid ( 𝑥 ∈ ℝ , 𝑦 ∈ ℝ ↦ { 𝑧 ∈ ℝ* ∣ ( 𝑥𝑧𝑧 < 𝑦 ) } ) = ( 𝑥 ∈ ℝ , 𝑦 ∈ ℝ ↦ { 𝑧 ∈ ℝ* ∣ ( 𝑥𝑧𝑧 < 𝑦 ) } )
10 xrex * ∈ V
11 10 rabex { 𝑧 ∈ ℝ* ∣ ( 𝑥𝑧𝑧 < 𝑦 ) } ∈ V
12 9 11 elrnmpo ( 𝐴 ∈ ran ( 𝑥 ∈ ℝ , 𝑦 ∈ ℝ ↦ { 𝑧 ∈ ℝ* ∣ ( 𝑥𝑧𝑧 < 𝑦 ) } ) ↔ ∃ 𝑥 ∈ ℝ ∃ 𝑦 ∈ ℝ 𝐴 = { 𝑧 ∈ ℝ* ∣ ( 𝑥𝑧𝑧 < 𝑦 ) } )
13 3 sseli ( 𝑥 ∈ ℝ → 𝑥 ∈ ℝ* )
14 13 adantr ( ( 𝑥 ∈ ℝ ∧ 𝑦 ∈ ℝ ) → 𝑥 ∈ ℝ* )
15 3 sseli ( 𝑦 ∈ ℝ → 𝑦 ∈ ℝ* )
16 15 adantl ( ( 𝑥 ∈ ℝ ∧ 𝑦 ∈ ℝ ) → 𝑦 ∈ ℝ* )
17 icoval ( ( 𝑥 ∈ ℝ*𝑦 ∈ ℝ* ) → ( 𝑥 [,) 𝑦 ) = { 𝑧 ∈ ℝ* ∣ ( 𝑥𝑧𝑧 < 𝑦 ) } )
18 14 16 17 syl2anc ( ( 𝑥 ∈ ℝ ∧ 𝑦 ∈ ℝ ) → ( 𝑥 [,) 𝑦 ) = { 𝑧 ∈ ℝ* ∣ ( 𝑥𝑧𝑧 < 𝑦 ) } )
19 18 eqcomd ( ( 𝑥 ∈ ℝ ∧ 𝑦 ∈ ℝ ) → { 𝑧 ∈ ℝ* ∣ ( 𝑥𝑧𝑧 < 𝑦 ) } = ( 𝑥 [,) 𝑦 ) )
20 19 eqeq2d ( ( 𝑥 ∈ ℝ ∧ 𝑦 ∈ ℝ ) → ( 𝐴 = { 𝑧 ∈ ℝ* ∣ ( 𝑥𝑧𝑧 < 𝑦 ) } ↔ 𝐴 = ( 𝑥 [,) 𝑦 ) ) )
21 20 rexbidva ( 𝑥 ∈ ℝ → ( ∃ 𝑦 ∈ ℝ 𝐴 = { 𝑧 ∈ ℝ* ∣ ( 𝑥𝑧𝑧 < 𝑦 ) } ↔ ∃ 𝑦 ∈ ℝ 𝐴 = ( 𝑥 [,) 𝑦 ) ) )
22 21 rexbiia ( ∃ 𝑥 ∈ ℝ ∃ 𝑦 ∈ ℝ 𝐴 = { 𝑧 ∈ ℝ* ∣ ( 𝑥𝑧𝑧 < 𝑦 ) } ↔ ∃ 𝑥 ∈ ℝ ∃ 𝑦 ∈ ℝ 𝐴 = ( 𝑥 [,) 𝑦 ) )
23 8 12 22 3bitri ( 𝐴 ∈ ran ( [,) ↾ ( ℝ × ℝ ) ) ↔ ∃ 𝑥 ∈ ℝ ∃ 𝑦 ∈ ℝ 𝐴 = ( 𝑥 [,) 𝑦 ) )