Metamath Proof Explorer


Theorem metcnpi

Description: Epsilon-delta property of a continuous metric space function, with function arguments as in metcnp . (Contributed by NM, 17-Dec-2007) (Revised by Mario Carneiro, 13-Nov-2013)

Ref Expression
Hypotheses metcn.2 𝐽 = ( MetOpen ‘ 𝐶 )
metcn.4 𝐾 = ( MetOpen ‘ 𝐷 )
Assertion metcnpi ( ( ( 𝐶 ∈ ( ∞Met ‘ 𝑋 ) ∧ 𝐷 ∈ ( ∞Met ‘ 𝑌 ) ) ∧ ( 𝐹 ∈ ( ( 𝐽 CnP 𝐾 ) ‘ 𝑃 ) ∧ 𝐴 ∈ ℝ+ ) ) → ∃ 𝑥 ∈ ℝ+𝑦𝑋 ( ( 𝑃 𝐶 𝑦 ) < 𝑥 → ( ( 𝐹𝑃 ) 𝐷 ( 𝐹𝑦 ) ) < 𝐴 ) )

Proof

Step Hyp Ref Expression
1 metcn.2 𝐽 = ( MetOpen ‘ 𝐶 )
2 metcn.4 𝐾 = ( MetOpen ‘ 𝐷 )
3 simpr ( ( ( 𝐶 ∈ ( ∞Met ‘ 𝑋 ) ∧ 𝐷 ∈ ( ∞Met ‘ 𝑌 ) ) ∧ 𝐹 ∈ ( ( 𝐽 CnP 𝐾 ) ‘ 𝑃 ) ) → 𝐹 ∈ ( ( 𝐽 CnP 𝐾 ) ‘ 𝑃 ) )
4 simpll ( ( ( 𝐶 ∈ ( ∞Met ‘ 𝑋 ) ∧ 𝐷 ∈ ( ∞Met ‘ 𝑌 ) ) ∧ 𝐹 ∈ ( ( 𝐽 CnP 𝐾 ) ‘ 𝑃 ) ) → 𝐶 ∈ ( ∞Met ‘ 𝑋 ) )
5 simplr ( ( ( 𝐶 ∈ ( ∞Met ‘ 𝑋 ) ∧ 𝐷 ∈ ( ∞Met ‘ 𝑌 ) ) ∧ 𝐹 ∈ ( ( 𝐽 CnP 𝐾 ) ‘ 𝑃 ) ) → 𝐷 ∈ ( ∞Met ‘ 𝑌 ) )
6 eqid 𝐽 = 𝐽
7 6 cnprcl ( 𝐹 ∈ ( ( 𝐽 CnP 𝐾 ) ‘ 𝑃 ) → 𝑃 𝐽 )
8 7 adantl ( ( ( 𝐶 ∈ ( ∞Met ‘ 𝑋 ) ∧ 𝐷 ∈ ( ∞Met ‘ 𝑌 ) ) ∧ 𝐹 ∈ ( ( 𝐽 CnP 𝐾 ) ‘ 𝑃 ) ) → 𝑃 𝐽 )
9 1 mopnuni ( 𝐶 ∈ ( ∞Met ‘ 𝑋 ) → 𝑋 = 𝐽 )
10 9 ad2antrr ( ( ( 𝐶 ∈ ( ∞Met ‘ 𝑋 ) ∧ 𝐷 ∈ ( ∞Met ‘ 𝑌 ) ) ∧ 𝐹 ∈ ( ( 𝐽 CnP 𝐾 ) ‘ 𝑃 ) ) → 𝑋 = 𝐽 )
11 8 10 eleqtrrd ( ( ( 𝐶 ∈ ( ∞Met ‘ 𝑋 ) ∧ 𝐷 ∈ ( ∞Met ‘ 𝑌 ) ) ∧ 𝐹 ∈ ( ( 𝐽 CnP 𝐾 ) ‘ 𝑃 ) ) → 𝑃𝑋 )
12 1 2 metcnp ( ( 𝐶 ∈ ( ∞Met ‘ 𝑋 ) ∧ 𝐷 ∈ ( ∞Met ‘ 𝑌 ) ∧ 𝑃𝑋 ) → ( 𝐹 ∈ ( ( 𝐽 CnP 𝐾 ) ‘ 𝑃 ) ↔ ( 𝐹 : 𝑋𝑌 ∧ ∀ 𝑧 ∈ ℝ+𝑥 ∈ ℝ+𝑦𝑋 ( ( 𝑃 𝐶 𝑦 ) < 𝑥 → ( ( 𝐹𝑃 ) 𝐷 ( 𝐹𝑦 ) ) < 𝑧 ) ) ) )
13 4 5 11 12 syl3anc ( ( ( 𝐶 ∈ ( ∞Met ‘ 𝑋 ) ∧ 𝐷 ∈ ( ∞Met ‘ 𝑌 ) ) ∧ 𝐹 ∈ ( ( 𝐽 CnP 𝐾 ) ‘ 𝑃 ) ) → ( 𝐹 ∈ ( ( 𝐽 CnP 𝐾 ) ‘ 𝑃 ) ↔ ( 𝐹 : 𝑋𝑌 ∧ ∀ 𝑧 ∈ ℝ+𝑥 ∈ ℝ+𝑦𝑋 ( ( 𝑃 𝐶 𝑦 ) < 𝑥 → ( ( 𝐹𝑃 ) 𝐷 ( 𝐹𝑦 ) ) < 𝑧 ) ) ) )
14 3 13 mpbid ( ( ( 𝐶 ∈ ( ∞Met ‘ 𝑋 ) ∧ 𝐷 ∈ ( ∞Met ‘ 𝑌 ) ) ∧ 𝐹 ∈ ( ( 𝐽 CnP 𝐾 ) ‘ 𝑃 ) ) → ( 𝐹 : 𝑋𝑌 ∧ ∀ 𝑧 ∈ ℝ+𝑥 ∈ ℝ+𝑦𝑋 ( ( 𝑃 𝐶 𝑦 ) < 𝑥 → ( ( 𝐹𝑃 ) 𝐷 ( 𝐹𝑦 ) ) < 𝑧 ) ) )
15 breq2 ( 𝑧 = 𝐴 → ( ( ( 𝐹𝑃 ) 𝐷 ( 𝐹𝑦 ) ) < 𝑧 ↔ ( ( 𝐹𝑃 ) 𝐷 ( 𝐹𝑦 ) ) < 𝐴 ) )
16 15 imbi2d ( 𝑧 = 𝐴 → ( ( ( 𝑃 𝐶 𝑦 ) < 𝑥 → ( ( 𝐹𝑃 ) 𝐷 ( 𝐹𝑦 ) ) < 𝑧 ) ↔ ( ( 𝑃 𝐶 𝑦 ) < 𝑥 → ( ( 𝐹𝑃 ) 𝐷 ( 𝐹𝑦 ) ) < 𝐴 ) ) )
17 16 rexralbidv ( 𝑧 = 𝐴 → ( ∃ 𝑥 ∈ ℝ+𝑦𝑋 ( ( 𝑃 𝐶 𝑦 ) < 𝑥 → ( ( 𝐹𝑃 ) 𝐷 ( 𝐹𝑦 ) ) < 𝑧 ) ↔ ∃ 𝑥 ∈ ℝ+𝑦𝑋 ( ( 𝑃 𝐶 𝑦 ) < 𝑥 → ( ( 𝐹𝑃 ) 𝐷 ( 𝐹𝑦 ) ) < 𝐴 ) ) )
18 17 rspccv ( ∀ 𝑧 ∈ ℝ+𝑥 ∈ ℝ+𝑦𝑋 ( ( 𝑃 𝐶 𝑦 ) < 𝑥 → ( ( 𝐹𝑃 ) 𝐷 ( 𝐹𝑦 ) ) < 𝑧 ) → ( 𝐴 ∈ ℝ+ → ∃ 𝑥 ∈ ℝ+𝑦𝑋 ( ( 𝑃 𝐶 𝑦 ) < 𝑥 → ( ( 𝐹𝑃 ) 𝐷 ( 𝐹𝑦 ) ) < 𝐴 ) ) )
19 14 18 simpl2im ( ( ( 𝐶 ∈ ( ∞Met ‘ 𝑋 ) ∧ 𝐷 ∈ ( ∞Met ‘ 𝑌 ) ) ∧ 𝐹 ∈ ( ( 𝐽 CnP 𝐾 ) ‘ 𝑃 ) ) → ( 𝐴 ∈ ℝ+ → ∃ 𝑥 ∈ ℝ+𝑦𝑋 ( ( 𝑃 𝐶 𝑦 ) < 𝑥 → ( ( 𝐹𝑃 ) 𝐷 ( 𝐹𝑦 ) ) < 𝐴 ) ) )
20 19 impr ( ( ( 𝐶 ∈ ( ∞Met ‘ 𝑋 ) ∧ 𝐷 ∈ ( ∞Met ‘ 𝑌 ) ) ∧ ( 𝐹 ∈ ( ( 𝐽 CnP 𝐾 ) ‘ 𝑃 ) ∧ 𝐴 ∈ ℝ+ ) ) → ∃ 𝑥 ∈ ℝ+𝑦𝑋 ( ( 𝑃 𝐶 𝑦 ) < 𝑥 → ( ( 𝐹𝑃 ) 𝐷 ( 𝐹𝑦 ) ) < 𝐴 ) )