Metamath Proof Explorer


Theorem lmmbr3

Description: Express the binary relation "sequence F converges to point P " in a metric space using an arbitrary upper set of integers. (Contributed by NM, 19-Dec-2006) (Revised by Mario Carneiro, 1-May-2014)

Ref Expression
Hypotheses lmmbr.2 𝐽 = ( MetOpen ‘ 𝐷 )
lmmbr.3 ( 𝜑𝐷 ∈ ( ∞Met ‘ 𝑋 ) )
lmmbr3.5 𝑍 = ( ℤ𝑀 )
lmmbr3.6 ( 𝜑𝑀 ∈ ℤ )
Assertion lmmbr3 ( 𝜑 → ( 𝐹 ( ⇝𝑡𝐽 ) 𝑃 ↔ ( 𝐹 ∈ ( 𝑋pm ℂ ) ∧ 𝑃𝑋 ∧ ∀ 𝑥 ∈ ℝ+𝑗𝑍𝑘 ∈ ( ℤ𝑗 ) ( 𝑘 ∈ dom 𝐹 ∧ ( 𝐹𝑘 ) ∈ 𝑋 ∧ ( ( 𝐹𝑘 ) 𝐷 𝑃 ) < 𝑥 ) ) ) )

Proof

Step Hyp Ref Expression
1 lmmbr.2 𝐽 = ( MetOpen ‘ 𝐷 )
2 lmmbr.3 ( 𝜑𝐷 ∈ ( ∞Met ‘ 𝑋 ) )
3 lmmbr3.5 𝑍 = ( ℤ𝑀 )
4 lmmbr3.6 ( 𝜑𝑀 ∈ ℤ )
5 1 2 lmmbr2 ( 𝜑 → ( 𝐹 ( ⇝𝑡𝐽 ) 𝑃 ↔ ( 𝐹 ∈ ( 𝑋pm ℂ ) ∧ 𝑃𝑋 ∧ ∀ 𝑥 ∈ ℝ+𝑗 ∈ ℤ ∀ 𝑘 ∈ ( ℤ𝑗 ) ( 𝑘 ∈ dom 𝐹 ∧ ( 𝐹𝑘 ) ∈ 𝑋 ∧ ( ( 𝐹𝑘 ) 𝐷 𝑃 ) < 𝑥 ) ) ) )
6 3 rexuz3 ( 𝑀 ∈ ℤ → ( ∃ 𝑗𝑍𝑘 ∈ ( ℤ𝑗 ) ( 𝑘 ∈ dom 𝐹 ∧ ( 𝐹𝑘 ) ∈ 𝑋 ∧ ( ( 𝐹𝑘 ) 𝐷 𝑃 ) < 𝑥 ) ↔ ∃ 𝑗 ∈ ℤ ∀ 𝑘 ∈ ( ℤ𝑗 ) ( 𝑘 ∈ dom 𝐹 ∧ ( 𝐹𝑘 ) ∈ 𝑋 ∧ ( ( 𝐹𝑘 ) 𝐷 𝑃 ) < 𝑥 ) ) )
7 4 6 syl ( 𝜑 → ( ∃ 𝑗𝑍𝑘 ∈ ( ℤ𝑗 ) ( 𝑘 ∈ dom 𝐹 ∧ ( 𝐹𝑘 ) ∈ 𝑋 ∧ ( ( 𝐹𝑘 ) 𝐷 𝑃 ) < 𝑥 ) ↔ ∃ 𝑗 ∈ ℤ ∀ 𝑘 ∈ ( ℤ𝑗 ) ( 𝑘 ∈ dom 𝐹 ∧ ( 𝐹𝑘 ) ∈ 𝑋 ∧ ( ( 𝐹𝑘 ) 𝐷 𝑃 ) < 𝑥 ) ) )
8 7 ralbidv ( 𝜑 → ( ∀ 𝑥 ∈ ℝ+𝑗𝑍𝑘 ∈ ( ℤ𝑗 ) ( 𝑘 ∈ dom 𝐹 ∧ ( 𝐹𝑘 ) ∈ 𝑋 ∧ ( ( 𝐹𝑘 ) 𝐷 𝑃 ) < 𝑥 ) ↔ ∀ 𝑥 ∈ ℝ+𝑗 ∈ ℤ ∀ 𝑘 ∈ ( ℤ𝑗 ) ( 𝑘 ∈ dom 𝐹 ∧ ( 𝐹𝑘 ) ∈ 𝑋 ∧ ( ( 𝐹𝑘 ) 𝐷 𝑃 ) < 𝑥 ) ) )
9 8 3anbi3d ( 𝜑 → ( ( 𝐹 ∈ ( 𝑋pm ℂ ) ∧ 𝑃𝑋 ∧ ∀ 𝑥 ∈ ℝ+𝑗𝑍𝑘 ∈ ( ℤ𝑗 ) ( 𝑘 ∈ dom 𝐹 ∧ ( 𝐹𝑘 ) ∈ 𝑋 ∧ ( ( 𝐹𝑘 ) 𝐷 𝑃 ) < 𝑥 ) ) ↔ ( 𝐹 ∈ ( 𝑋pm ℂ ) ∧ 𝑃𝑋 ∧ ∀ 𝑥 ∈ ℝ+𝑗 ∈ ℤ ∀ 𝑘 ∈ ( ℤ𝑗 ) ( 𝑘 ∈ dom 𝐹 ∧ ( 𝐹𝑘 ) ∈ 𝑋 ∧ ( ( 𝐹𝑘 ) 𝐷 𝑃 ) < 𝑥 ) ) ) )
10 5 9 bitr4d ( 𝜑 → ( 𝐹 ( ⇝𝑡𝐽 ) 𝑃 ↔ ( 𝐹 ∈ ( 𝑋pm ℂ ) ∧ 𝑃𝑋 ∧ ∀ 𝑥 ∈ ℝ+𝑗𝑍𝑘 ∈ ( ℤ𝑗 ) ( 𝑘 ∈ dom 𝐹 ∧ ( 𝐹𝑘 ) ∈ 𝑋 ∧ ( ( 𝐹𝑘 ) 𝐷 𝑃 ) < 𝑥 ) ) ) )