@@ -64,7 +64,7 @@ Compared to most expositions of the subject, we work with explicit
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universe levels.
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We also [fully discuss and emphasize](HoTT-UF-Agda.html#summary) that
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- classical axioms can be assumed consistently in univalent mathematics.
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+ non-constructive classical axioms can be assumed consistently in univalent mathematics.
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**Keywords.** Univalent mathematics. Univalent foundations. Univalent
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type theory. Univalence axiom. `∞`-Groupoid. Homotopy type. Type
@@ -4295,8 +4295,9 @@ What characterizes univalent mathematics is not the univalence
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axiom. We have defined and studied the main concepts of univalent
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mathematics in a pure, spartan MLTT. It is the concepts of hlevel,
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including singleton, subsingleton and set, and the notion of
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- equivalence. Univalence *is* a fundamental ingredient, but first we
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- need the correct notion of equivalence to be able to formulate it.
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+ equivalence that are at the heart of univalent mathematics. Univalence
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+ *is* a fundamental ingredient, but first we need the correct notion of
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+ equivalence to be able to formulate it.
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*Remark*. If we formulate univalence with invertible maps instead of
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equivalences, we get a statement that is provably false in MLTT, and
@@ -9562,13 +9563,13 @@ We begin with the following technical lemma:
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r (s (a , b)) ≡⟨ refl _ ⟩
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r (to-×-≡ (f' a , g' b)) ≡⟨ refl _ ⟩
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(f x₀ x₁ (ap pr₁ (to-×-≡ (f' a , g' b))) ,
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- g y₀ y₁ (ap pr₂ (to-×-≡ (f' a , g' b)))) ≡⟨ ii ⟩
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- (f x₀ x₁ (f' a) , g y₀ y₁ (g' b)) ≡⟨ iii ⟩
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+ g y₀ y₁ (ap pr₂ (to-×-≡ (f' a , g' b)))) ≡⟨ ii ⟩
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+ (f x₀ x₁ (f' a) , g y₀ y₁ (g' b)) ≡⟨ iii ⟩
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a , b ∎
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where
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- ii = ap₂ (λ p q → f x₀ x₁ p , g y₀ y₁ q)
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- (ap-pr₁-to-×-≡ (f' a) (g' b))
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- (ap-pr₂-to-×-≡ (f' a) (g' b))
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+ ii = ap₂ (λ p q → f x₀ x₁ p , g y₀ y₁ q)
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+ (ap-pr₁-to-×-≡ (f' a) (g' b))
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+ (ap-pr₂-to-×-≡ (f' a) (g' b))
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iii = to-×-≡ (inverse-is-section (f x₀ x₁) (i x₀ x₁) a ,
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inverse-is-section (g y₀ y₁) (j y₀ y₁) b)
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