Complex nhds has Basis square
Complex.nhds_hasBasis_square
Plain-language statement
At every point , the axis-parallel closed squares centered at with positive half-width form a neighborhood basis. Equivalently, a set is a neighborhood of exactly when it contains one of these sufficiently small squares.
Exact Lean statement
theorem Complex.nhds_hasBasis_square (p : ℂ) : (𝓝 p).HasBasis (0 < ·) (Square p ·)
Formal artifact
Lean source
theorem Complex.nhds_hasBasis_square (p : ℂ) : (𝓝 p).HasBasis (0 < ·) (Square p ·) := by suffices (𝓝 p.re ×ˢ 𝓝 p.im).HasBasis (0 < ·) (equivRealProdCLM.symm.toHomeomorph ⁻¹' Square p ·) by simpa only [← nhds_prod_eq, Homeomorph.map_nhds_eq, Homeomorph.image_preimage] using! this.map equivRealProdCLM.symm.toHomeomorph apply ((nhds_basis_Icc_pos p.re).prod_same_index_mono (nhds_basis_Icc_pos p.im) ?_ ?_).congr · intro; rfl · intros rw [← uIcc_of_lt (by linarith), ← uIcc_of_lt (by linarith)] simpa [Square, Rectangle] using by ring_nf all_goals exact (antitone_const_tsub.Icc (monotone_id.const_add _)).monotoneOn _- Project
- Prime Number Theorem and More
- License
- Apache-2.0
- Commit
- a93551347dce
- Source
- PrimeNumberTheoremAnd/Rectangle.lean:253-264
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Person-level attribution pending.
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Plain-language statement
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Source project: Prime Number Theorem and More
Person-level attribution pending.
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Plain-language statement
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Source project: Prime Number Theorem and More
Person-level attribution pending.