27 lines
644 B
Agda
27 lines
644 B
Agda
module Exercises1 where
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open import Agda.Primitive
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open import foundation-core.empty-types
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open import foundation-core.equivalences
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open import foundation-core.negation
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open import foundation.dependent-pair-types
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open import foundation.identity-types
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open import foundation.univalence
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open import foundation.sections
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open import foundation.retractions
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_≡_ = _＝_
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⊥ = empty
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equal-to-zero : {A : Set} (f : ¬ A) → A ≡ ⊥
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equal-to-zero {A} f = eq-equiv A ⊥ eqv
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where
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s : section f
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s = (λ ()) , λ x → ex-falso x
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r : retraction f
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r = (λ ()) , λ x → ex-falso (f x)
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eqv : A ≃ ⊥
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eqv = f , s , r
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