[Merged by Bors] - feat: add a TietzeExtension class#9788
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[Merged by Bors] - feat: add a TietzeExtension class#9788
TietzeExtension class#9788Conversation
TietzeExtension class
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I'll give this a deeper look soon, but a first comment:
Why not provide an instance/reducible-def for finite dimensional T2 real TVS, by reducing it to products using LinearEquiv.toContinuousLinearEquiv. Then it will apply directly to |
urkud
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Jan 16, 2024
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@ADedecker I've implemented your nice suggestion. It can't be an instance because there is no way for Lean to know which scalar field is intended, so it's just a theorem. Optionally, I could provide in additional an actual instance, where the scalar field is just assumed to be |
urkud
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Jan 23, 2024
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Thanks 🎉 bors merge |
mathlib-bors bot
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Feb 15, 2024
This adds a class `TietzeExtension` to encode the Tietze extension theorem as a type class that can be satisfied by various types. For now, we provide instances for `ℝ`, `ℝ≥0`, `ℂ`, `IsROrC 𝕜`, pi types, product types, as well as constructors via homeomorphisms or retracts of a `TietzeExtension` space, and also a constructor for finite dimensional topological vector spaces.
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Pull request successfully merged into master. Build succeeded: |
TietzeExtension classTietzeExtension class
riccardobrasca
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Feb 18, 2024
This adds a class `TietzeExtension` to encode the Tietze extension theorem as a type class that can be satisfied by various types. For now, we provide instances for `ℝ`, `ℝ≥0`, `ℂ`, `IsROrC 𝕜`, pi types, product types, as well as constructors via homeomorphisms or retracts of a `TietzeExtension` space, and also a constructor for finite dimensional topological vector spaces.
dagurtomas
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Mar 22, 2024
This adds a class `TietzeExtension` to encode the Tietze extension theorem as a type class that can be satisfied by various types. For now, we provide instances for `ℝ`, `ℝ≥0`, `ℂ`, `IsROrC 𝕜`, pi types, product types, as well as constructors via homeomorphisms or retracts of a `TietzeExtension` space, and also a constructor for finite dimensional topological vector spaces.
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This adds a class
TietzeExtensionto encode the Tietze extension theorem as a type class that can be satisfied by various types. For now, we provide instances forℝ,ℝ≥0,ℂ,IsROrC 𝕜, pi types, product types, as well as constructors via homeomorphisms or retracts of aTietzeExtensionspace, and also a constructor for finite dimensional topological vector spaces.