CHANGELOG.md

Version 1.7

The library has been tested using Agda 2.6.2.

Highlights

• New module for making system calls during type checking, Reflection.External, which re-exports Agda.Builtin.Reflection.External.

• New predicate for lists that are enumerations their type in Data.List.Relation.Unary.Enumerates.

• New weak induction schemes in Data.Fin.Induction that allows one to avoid the complicated use of Acc/inject/raise when proving inductive properties over finite sets.

Bug-fixes

• Added missing module Function.Metric which re-exports Function.Metric.(Core/Definitions/Structures/Bundles). This module was referred to in the documentation of its children but until now was not present.

• Added missing fixity declaration to _<_ in Relation.Binary.Construct.NonStrictToStrict.

Non-backwards compatible changes

Floating-point arithmetic

• The functions in Data.Float.Base were updated following changes upstream, in Agda.Builtin.Float, see agda/agda#4885.

• The bitwise binary relations on floating-point numbers (_<_, _≈ᵇ_, _==_) have been removed without replacement, as they were deeply unintuitive, e.g., ∀ x → x < -x.

Reflection

• The representation of reflected syntax in Reflection.Term, Reflection.Pattern, Reflection.Argument and Reflection.Argument.Information has been updated to match the new representation used in Agda 2.6.2. Specifically, the following changes were made:

  • The type of the var constructor of the Pattern datatype has been changed from (x : String) → Pattern to (x : Int) → Pattern.

  • The type of the dot constructor of the Pattern datatype has been changed from Pattern to (t : Term) → Pattern.

  • The types of the clause and absurd-clause constructors of the Clause datatype now take an extra argument (tel : Telescope), where Telescope = List (String × Arg Type).

  • The following constructors have been added to the Sort datatype: prop : (t : Term) → Sort, propLit : (n : Nat) → Sort, and inf : (n : Nat) → Sort.

  • In Reflection.Argument.Information the function relevance was replaced by modality.

  • The type of the arg-info constructor is now (v : Visibility) (m : Modality) → ArgInfo.

  • In Reflection.Argument (as well as Reflection) there is a new pattern synonym defaultModality, and the pattern synonyms vArg, hArg and iArg have been changed.

  • Two new modules have been added, Reflection.Argument.Modality and Reflection.Argument.Quantity. The constructors of the types Modality and Quantity are reexported from Reflection.

Sized types

• Sized types are no longer considered safe in Agda 2.6.2. As a result, all modules that use --sized-types no longer have the --safe flag. For a full list of affected modules, refer to the relevant commit

• In order to maintain the safety of Data.Nat.Pseudorandom.LCG, the function stream that relies on the newly unsafe Codata modules has been moved to the new module Data.Nat.Pseudorandom.LCG.Unsafe.

• In order to maintain the safety of the modules in the Codata.Musical directory, the functions fromMusical and toMusical defined in:

  Codata.Musical.Colist
  Codata.Musical.Conat
  Codata.Musical.Cofin
  Codata.Musical.M
  Codata.Musical.Stream
  

  have been moved to a new module Codata.Musical.Conversion and renamed to X.fromMusical and X.toMusical for each of Codata.Musical.X.

• In order to maintain the safety of Data.Container(.Indexed), the greatest fixpoint of containers, ν, has been moved from Data.Container(.Indexed) to a new module Data.Container(.Indexed).Fixpoints.Guarded which also re-exports the least fixpoint.

Other

• Replaced existing O(n) implementation of Data.Nat.Binary.fromℕ with a new O(log n) implementation. The old implementation is maintained under Data.Nat.Binary.fromℕ' and proven to be equivalent to the new one.

• Data.Maybe.Base now re-exports the definition of Maybe given by Agda.Builtin.Maybe. The Foreign.Haskell modules and definitions corresponding to Maybe have been removed. See the release notes of Agda 2.6.2 for more information.

Deprecated modules

Deprecated names

New modules

• New module for making system calls during type checking:

  Reflection.External

• New modules for universes and annotations of reflected syntax:

  Reflection.Universe
  Reflection.Annotated
  Reflection.Annotated.Free
  

• Added new module for unary relations over sized types now that Size lives in it's own universe since Agda 2.6.2.

  Relation.Unary.Sized

• Metrics specialised to co-domains with rational numbers:

  Function.Metric.Rational
  Function.Metric.Rational.Definitions
  Function.Metric.Rational.Structures
  Function.Metric.Rational.Bundles
  

• Lists that contain every element of a type:

  Data.List.Relation.Unary.Enumerates.Setoid
  Data.List.Relation.Unary.Enumerates.Setoid.Properties
  

• (Unsafe) sized W type:

  Data.W.Sized
  

• (Unsafe) container fixpoints:

  Data.Container.Fixpoints.Sized
  

Other minor additions

• Added new relations to Data.Fin.Base:

  _≥_ = ℕ._≥_ on toℕ
  _>_ = ℕ._>_ on toℕ

• Added new proofs to Data.Fin.Induction:

  >-wellFounded   : WellFounded {A = Fin n} _>_
  
  <-weakInduction : P zero      → (∀ i → P (inject₁ i) → P (suc i)) → ∀ i → P i
  >-weakInduction : P (fromℕ n) → (∀ i → P (suc i) → P (inject₁ i)) → ∀ i → P i

• Added new proofs to Relation.Binary.Properties.Setoid:

  respʳ-flip : _≈_ Respectsʳ (flip _≈_)
  respˡ-flip : _≈_ Respectsˡ (flip _≈_)

• Added new function to Data.Fin.Base:

  pinch : Fin n → Fin (suc n) → Fin n

• Added new proofs to Data.Fin.Properties:

  pinch-surjective : Surjective _≡_ (pinch i)
  pinch-mono-≤     : (pinch i) Preserves _≤_ ⟶ _≤_

• Added new proofs to Data.Nat.Binary.Properties:

  fromℕ≡fromℕ'  : fromℕ ≗ fromℕ'
  toℕ-fromℕ'    : toℕ ∘ fromℕ' ≗ id
  fromℕ'-homo-+ : fromℕ' (m ℕ.+ n) ≡ fromℕ' m + fromℕ' n

• Rewrote proofs in Data.Nat.Binary.Properties for new implementation of fromℕ:

  toℕ-fromℕ    : toℕ ∘ fromℕ ≗ id
  fromℕ-homo-+ : fromℕ (m ℕ.+ n) ≡ fromℕ m + fromℕ n

• Added new proof to Data.Nat.DivMod:

  m/n≤m : (m / n) {≢0} ≤ m

• Added new type in Size:

  SizedSet ℓ = Size → Set ℓ