This commit is contained in:
ajeffrey@roblox.com 2022-05-24 19:26:00 -05:00
parent 02e65d8888
commit a3866d544f
5 changed files with 85 additions and 49 deletions

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@ -13,7 +13,7 @@ open import Properties.Contradiction using (CONTRADICTION; ¬)
open import Properties.Functions using (_∘_)
open import Properties.Subtyping using (<:-refl; <:-trans; ≮:-trans-<:; <:-trans-≮:; <:-never; <:-unknown; <:--left; <:--right; <:--lub; ≮:--left; ≮:--right; <:-∩-left; <:-∩-right; <:-∩-glb; ≮:-∩-left; ≮:-∩-right; dec-language; scalar-<:; <:-everything; <:-function; ≮:-function-left; ≮:-function-right; <:-impl-¬≮:; <:-intersect; <:-function-∩-; <:-function-∩; <:-function-never; <:-union; ≮:-left-; ≮:-right-; <:-∩-distr-; <:-impl-⊇; language-comp)
open import Properties.TypeNormalization using (FunType; Normal; never; unknown; _∩_; __; _⇒_; normal; <:-normalize; normalize-<:; normal-∩ⁿ; normal-∪ⁿ; -<:-∪ⁿ; ∪ⁿ-<:-; ∩ⁿ-<:-∩; ∩-<:-∩ⁿ; normalᶠ; function-top)
open import Properties.TypeSaturation using (Overloads; Saturated; _⊆ᵒ_; defn; here; left; right; ov-language; ov-<:; saturated; normal-saturate; normal-overload-src; normal-overload-tgt; saturate-<:; <:-saturate)
open import Properties.TypeSaturation using (Overloads; Saturated; _⊆ᵒ_; _<:ᵒ_; defn; here; left; right; ov-language; ov-<:; saturated; normal-saturate; normal-overload-src; normal-overload-tgt; saturate-<:; <:-saturate; <:ᵒ-impl-<:; _>>=ˡ_; _>>=ʳ_)
open import Properties.Equality using (_≢_)
fun-function : {F} FunType F Language F function
@ -30,9 +30,10 @@ fun-¬scalar s (F ∩ G) (p₁ , p₂) = fun-¬scalar s G p₂
-- Honest this terminates, since saturation maintains the depth of nested arrows
{-# TERMINATING #-}
dec-subtypingˢⁿ : {T U} Scalar T Normal U Either (T ≮: U) (T <: U)
dec-subtypingˢᶠ : {T U} FunType T Saturated T FunType U Either (T ≮: U) (T <: U)
dec-subtypingᶠ : {T U} FunType T FunType U Either (T ≮: U) (T <: U)
dec-subtypingᶠⁿ : {T U} FunType T Normal U Either (T ≮: U) (T <: U)
dec-subtypingˢᶠᵒ : {F S T} FunType F Saturated F FunType (S T) (S ≮: never) Either (F ≮: (S T)) (F <:ᵒ (S T))
dec-subtypingˢᶠ : {F G} FunType F Saturated F FunType G Either (F ≮: G) (F <: G)
dec-subtypingᶠ : {F G} FunType F FunType G Either (F ≮: G) (F <: G)
dec-subtypingᶠⁿ : {F U} FunType F Normal U Either (F ≮: U) (F <: U)
dec-subtypingⁿ : {T U} Normal T Normal U Either (T ≮: U) (T <: U)
dec-subtyping : T U Either (T ≮: U) (T <: U)
@ -40,13 +41,7 @@ dec-subtypingˢⁿ T U with dec-language _ (scalar T)
dec-subtypingˢⁿ T U | Left p = Left (witness (scalar T) (scalar T) p)
dec-subtypingˢⁿ T U | Right p = Right (scalar-<: T p)
dec-subtypingˢᶠ F (G H) with dec-subtypingˢᶠ F G | dec-subtypingˢᶠ F H
dec-subtypingˢᶠ F (G H) | Left F≮:G | _ = Left (≮:-∩-left F≮:G)
dec-subtypingˢᶠ F (G H) | _ | Left F≮:H = Left (≮:-∩-right F≮:H)
dec-subtypingˢᶠ F (G H) | Right F<:G | Right F<:H = Right (<:-∩-glb F<:G F<:H)
dec-subtypingˢᶠ F (defn sat-∩ sat-) (S T) with dec-subtypingⁿ S never
dec-subtypingˢᶠ F (defn sat-∩ sat-) (S T) | Right S<:never = Right (<:-trans (function-top F) (<:-trans <:-function-never (<:-function S<:never <:-refl)))
dec-subtypingˢᶠ {F} {S T} Fᶠ (defn sat-∩ sat-) (Sⁿ Tⁿ) | Left (witness s₀ Ss₀ never) = result (top Fᶠ (λ o o)) where
dec-subtypingˢᶠᵒ {F} {S} {T} Fᶠ (defn sat-∩ sat-) (Sⁿ Tⁿ) (witness s₀ Ss₀ never) = result (top Fᶠ (λ o o)) where
data Top G : Set where
@ -64,7 +59,7 @@ dec-subtypingˢᶠ {F} {S ⇒ T} Fᶠ (defn sat-∩ sat-) (Sⁿ ⇒ Tⁿ) | L
top (Gᶠ Hᶠ) G⊆F | defn Rᵗ Sᵗ p p₁ | defn Tᵗ Uᵗ q q₁ | defn n r r₁ = defn _ _ n
(λ { (left o) <:-trans (<:-trans (p₁ o) <:--left) r ; (right o) <:-trans (<:-trans (q₁ o) <:--right) r })
result : Top F Either (F ≮: (S T)) (F <: (S T))
result : Top F Either (F ≮: (S T)) (F <: (S T))
result (defn Sᵗ Tᵗ oᵗ srcᵗ) with dec-subtypingⁿ Sⁿ (normal-overload-src Fᶠ oᵗ)
result (defn Sᵗ Tᵗ oᵗ srcᵗ) | Left (witness s Ss ¬Sᵗs) = Left (witness (function-err s) (ov-language Fᶠ (λ o function-err (<:-impl-⊇ (srcᵗ o) s ¬Sᵗs))) (function-err Ss))
result (defn Sᵗ Tᵗ oᵗ srcᵗ) | Right S<:Sᵗ = result₀ (largest Fᶠ (λ o o)) where
@ -104,10 +99,10 @@ dec-subtypingˢᶠ {F} {S ⇒ T} Fᶠ (defn sat-∩ sat-) (Sⁿ ⇒ Tⁿ) | L
; (right o) T<:T <:-trans (src₂ o T<:T) (<:-trans <:--right src)
})
result₀ : LargestSrc F Either (F ≮: (S T)) (F <: (S T))
result₀ : LargestSrc F Either (F ≮: (S T)) (F <: (S T))
result₀ (no S₀ T₀ o₀ (witness t T₀t ¬Tt) tgt₀) = Left (witness (function-ok s₀ t) (ov-language Fᶠ (λ o function-ok₂ (tgt₀ o t T₀t))) (function-ok Ss₀ ¬Tt))
result₀ (yes S₀ T₀ o₀ T₀<:T src₀) with dec-subtypingⁿ Sⁿ (normal-overload-src Fᶠ o₀)
result₀ (yes S₀ T₀ o₀ T₀<:T src₀) | Right S<:S₀ = Right (ov-<: Fᶠ o₀ (<:-function S<:S₀ T₀<:T))
result₀ (yes S₀ T₀ o₀ T₀<:T src₀) | Right S<:S₀ = Right (defn o₀ S<:S₀ T₀<:T)
result₀ (yes S₀ T₀ o₀ T₀<:T src₀) | Left (witness s Ss ¬S₀s) = Left (result₁ (smallest Fᶠ (λ o o))) where
data SmallestTgt (G : Type) : Set where
@ -141,6 +136,16 @@ dec-subtypingˢᶠ {F} {S ⇒ T} Fᶠ (defn sat-∩ sat-) (Sⁿ ⇒ Tⁿ) | L
lemma {S} o | Left ¬Ss = function-ok₁ ¬Ss
lemma {S} o | Right Ss = function-ok₂ (tgt₁ o Ss t T₁t)
dec-subtypingˢᶠ F (S T) with dec-subtypingⁿ S never
dec-subtypingˢᶠ F (S T) | Right S<:never = Right (<:-trans (function-top F) (<:-trans <:-function-never (<:-function S<:never <:-refl)))
dec-subtypingˢᶠ F (S T) | Left S≮:never with dec-subtypingˢᶠᵒ F (S T) S≮:never
dec-subtypingˢᶠ F (S T) | Left S≮:never | Left F≮:S⇒T = Left F≮:S⇒T
dec-subtypingˢᶠ F (S T) | Left S≮:never | Right F<:ᵒS⇒T = Right (<:ᵒ-impl-<: F F<:ᵒS⇒T)
dec-subtypingˢᶠ F (G H) with dec-subtypingˢᶠ F G | dec-subtypingˢᶠ F H
dec-subtypingˢᶠ F (G H) | Left F≮:G | _ = Left (≮:-∩-left F≮:G)
dec-subtypingˢᶠ F (G H) | _ | Left F≮:H = Left (≮:-∩-right F≮:H)
dec-subtypingˢᶠ F (G H) | Right F<:G | Right F<:H = Right (<:-∩-glb F<:G F<:H)
dec-subtypingᶠ F G with dec-subtypingˢᶠ (normal-saturate F) (saturated F) G
dec-subtypingᶠ F G | Left H≮:G = Left (<:-trans-≮: (saturate-<: F) H≮:G)
dec-subtypingᶠ F G | Right H<:G = Right (<:-trans (<:-saturate F) H<:G)
@ -176,3 +181,12 @@ dec-subtypingⁿ (S T) U | Right p | Right q = Right (<:--lub p q)
dec-subtyping T U with dec-subtypingⁿ (normal T) (normal U)
dec-subtyping T U | Left p = Left (<:-trans-≮: (normalize-<: T) (≮:-trans-<: p (<:-normalize U)))
dec-subtyping T U | Right p = Right (<:-trans (<:-normalize T) (<:-trans p (normalize-<: U)))
-- As a corollary, for saturated functions
-- <:ᵒ coincides with <:, that is F is a subtype of (S ⇒ T) precisely
-- when one of its overloads is.
<:-impl-<:ᵒ : {F S T} FunType F Saturated F (S ≮: never) (F <: (S T)) (F <:ᵒ (S T))
<:-impl-<: {F} {S} {T} Fᶠ S≮:never F<:S⇒T with dec-subtypingˢᶠᵒ Fᶠ (normal S normal T) (<:-trans-≮: (<:-normalize S) S≮:never)
<:-impl-<: {F} {S} {T} Fᶠ S≮:never F<:S⇒T | Left F≮:S⇒T = CONTRADICTION (<:-impl-¬≮: (<:-trans F<:S⇒T (<:-normalize (S T))) F≮:S⇒T)
<:-impl-<: {F} {S} {T} Fᶠ S≮:never F<:S⇒T | Right F<:ᵒS⇒T = F<:ᵒS⇒T >>=ˡ <:-normalize S >>=ʳ normalize-<: T

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@ -3,15 +3,15 @@
module Properties.ResolveOverloads where
open import FFI.Data.Either using (Left; Right)
open import Luau.Subtyping using (_<:_; _≮:_)
open import Luau.Subtyping using (_<:_; _≮:_; Language; witness; scalar; unknown; never; function-ok)
open import Luau.Type using (Type ; _⇒_; unknown; never)
open import Luau.TypeSaturation using (saturate)
open import Properties.Contradiction using (CONTRADICTION)
open import Properties.DecSubtyping using (dec-subtyping)
open import Properties.DecSubtyping using (dec-subtyping; dec-subtypingⁿ; <:-impl-<:ᵒ)
open import Properties.Functions using (_∘_)
open import Properties.Subtyping using (<:-refl; <:-trans; <:-∩-left; <:-∩-right; <:-∩-glb; <:-impl-¬≮:; <:-unknown; function-≮:-never)
open import Properties.TypeNormalization using (Normal; FunType; normal; _⇒_; _∩_; __; never; unknown; <:-normalize)
open import Properties.TypeSaturation using (Overloads; Saturated; _⊆ᵒ_; normal-saturate; saturated; defn; here; left; right)
open import Properties.Subtyping using (<:-refl; <:-trans; <:-trans-≮:; ≮:-trans-<:; <:-∩-left; <:-∩-right; <:-∩-glb; <:--right; <:-impl-¬≮:; <:-unknown; <:-function; function-≮:-never; <:-never; unknown-≮:-function; scalar-≮:-function)
open import Properties.TypeNormalization using (Normal; FunType; normal; _⇒_; _∩_; __; never; unknown; <:-normalize; normalize-<:)
open import Properties.TypeSaturation using (Overloads; Saturated; _⊆ᵒ_; _<:ᵒ_; normal-saturate; saturated; <:-saturate; saturate-<:; defn; here; left; right)
data ResolvedTo F G R : Set where
@ -29,15 +29,13 @@ data ResolvedTo F G R : Set where
--------------------------------------------
ResolvedTo F G R
never :
(F <: never)
--------------------------------------------
ResolvedTo F G R
Resolved : Type Type Set
Resolved F R = ResolvedTo F F R
target : {F R} Resolved F R Type
target (yes _ T _ _ _) = T
target (no _) = unknown
resolveˢ : {F G R} FunType G Saturated F Normal R (G ⊆ᵒ F) ResolvedTo F G R
resolveˢ (Sⁿ Tⁿ) (defn sat-∩ sat-) Rⁿ G⊆F with dec-subtypingⁿ Rⁿ Sⁿ
resolveˢ (Sⁿ Tⁿ) (defn sat-∩ sat-) Rⁿ G⊆F | Left R≮:S = no (λ { here R≮:S })
@ -52,27 +50,46 @@ resolveˢ (Gᶠ ∩ Hᶠ) (defn sat-∩ sat-) Rⁿ G⊆F | no src₁ | yes S
yes _ _ o₂ R<:S₂ (λ { (left o) p CONTRADICTION (<:-impl-¬≮: p (src₁ o)) ; (right o) p tgt₂ o p })
resolveˢ (Gᶠ Hᶠ) (defn sat-∩ sat-) Rⁿ G⊆F | no src₁ | no src₂ =
no (λ { (left o) src₁ o ; (right o) src₂ o })
resolveˢ (Gᶠ Hᶠ) (defn sat-∩ sat-) Rⁿ G⊆F | _ | never q = never q
resolveˢ (Gᶠ Hᶠ) (defn sat-∩ sat-) Rⁿ G⊆F | never p | _ = never p
resolveᶠ : {F R} FunType F Normal R Resolved (saturate F) R
resolveᶠ Fᶠ Rⁿ = resolveˢ (normal-saturate Fᶠ) (saturated Fᶠ) Rⁿ (λ o o)
resolveⁿ : {F R} Normal F Normal R Resolved (saturate F) R
resolveⁿ (Sⁿ Tⁿ) Rⁿ = resolveᶠ (Sⁿ Tⁿ) Rⁿ
resolveⁿ (Fᶠ Gᶠ) Rⁿ = resolveᶠ (Fᶠ Gᶠ) Rⁿ
resolveⁿ (Sⁿ ) Rⁿ = no (λ ())
resolveⁿ never Rⁿ = never <:-refl
resolveⁿ unknown Rⁿ = no (λ ())
resolveⁿ : {F R} Normal F Normal R Type
resolveⁿ (Sⁿ Tⁿ) Rⁿ = target (resolveᶠ (Sⁿ Tⁿ) Rⁿ)
resolveⁿ (Fᶠ Gᶠ) Rⁿ = target (resolveᶠ (Fᶠ Gᶠ) Rⁿ)
resolveⁿ (Sⁿ ) Rⁿ = unknown
resolveⁿ unknown Rⁿ = unknown
resolveⁿ never Rⁿ = never
resolve : Type Type Type
resolve F R with resolveⁿ (normal F) (normal R)
resolve F R | yes S T o R<:S p = T
resolve F R | no p = unknown
resolve F R | never p = never
resolve F R = resolveⁿ (normal F) (normal R)
<:-target-⇒ : {R S T} (r : Resolved (S T) R) (T <: target r)
<:-target-⇒ (yes here x₁ x₂) = <:-refl
<:-target-⇒ (no x) = <:-unknown
<:-resolveⁿ : {R S T} (Fⁿ : Normal (S T)) (Rⁿ : Normal R) T <: resolveⁿ Fⁿ Rⁿ
<:-resolveⁿ (Sⁿ Tⁿ) Rⁿ = <:-target-⇒ (resolveˢ (Sⁿ Tⁿ) (saturated (Sⁿ Tⁿ)) Rⁿ (λ o o))
<:-resolve : {R S T} T <: resolve (S T) R
<:-resolve {R} {S} {T} with resolveⁿ (normal (S T)) (normal R)
<:-resolve {R} {S} {T} | yes Sⁿ Tⁿ here Rⁿ<:Sʳ p = <:-normalize T
<:-resolve {R} {S} {T} | no p = <:-unknown
<:-resolve {R} {S} {T} | never p = CONTRADICTION (<:-impl-¬≮: p function-≮:-never)
<:-resolve {R} {S} {T} = <:-trans (<:-normalize T) (<:-resolveⁿ (normal (S T)) (normal R))
resolveˢ-<:-⇒ : {F R U} (FunType F) (Saturated F) (r : Resolved F R) (R ≮: never) (F <: (R U)) (target r <: U)
resolveˢ-<:-⇒ Fᶠ r R≮:never F<:R⇒U with <:-impl-<:ᵒ Fᶠ R≮:never F<:R⇒U
resolveˢ-<:-⇒ Fᶠ (yes R<:Sʳ tgtʳ) R≮:never F<:R⇒U | defn o o₁ o₂ = <:-trans (tgtʳ o o₁) o₂
resolveˢ-<:-⇒ Fᶠ (no tgtʳ) R≮:never F<:R⇒U | defn o o₁ o₂ = CONTRADICTION (<:-impl-¬≮: o₁ (tgtʳ o))
resolveⁿ-<:-⇒ : {F R U} (Fⁿ : Normal F) (Rⁿ : Normal R) (R ≮: never) (F <: (R U)) (resolveⁿ Fⁿ Rⁿ <: U)
resolveⁿ-<:-⇒ (Sⁿ Tⁿ) Rⁿ R≮:never F<:R⇒U = resolveˢ-<:-⇒ (normal-saturate (Sⁿ Tⁿ)) (saturated (Sⁿ Tⁿ)) (resolveˢ (normal-saturate (Sⁿ Tⁿ)) (saturated (Sⁿ Tⁿ)) Rⁿ (λ o o)) R≮:never F<:R⇒U
resolveⁿ-<:-⇒ (Fⁿ Gⁿ) Rⁿ R≮:never F<:R⇒U = resolveˢ-<:-⇒ (normal-saturate (Fⁿ Gⁿ)) (saturated (Fⁿ Gⁿ)) (resolveˢ (normal-saturate (Fⁿ Gⁿ)) (saturated (Fⁿ Gⁿ)) Rⁿ (λ o o)) R≮:never (<:-trans (saturate-<: (Fⁿ Gⁿ)) F<:R⇒U)
resolveⁿ-<:-⇒ (Sⁿ ) Rⁿ R≮:never F<:R⇒U = CONTRADICTION (<:-impl-¬≮: F<:R⇒U (<:-trans-≮: <:--right (scalar-≮:-function )))
resolveⁿ-<:-⇒ never Rⁿ R≮:never F<:R⇒U = <:-never
resolveⁿ-<:-⇒ unknown Rⁿ R≮:never F<:R⇒U = CONTRADICTION (<:-impl-¬≮: F<:R⇒U unknown-≮:-function)
resolve-<:-⇒ : {F R U} (R ≮: never) (F <: (R U)) (resolve F R <: U)
resolve-<:-⇒ {F} {R} R≮:never F<:R⇒U = resolveⁿ-<:-⇒ (normal F) (normal R) (<:-trans-≮: (<:-normalize R) R≮:never) (<:-trans (normalize-<: F) (<:-trans F<:R⇒U (<:-function (normalize-<: R) <:-refl)))
resolve-≮:-⇒ : {F R U} (R ≮: never) (resolve F R ≮: U) (F ≮: (R U))
resolve-≮:-⇒ {F} {R} {U} R≮:never FR≮:U with dec-subtyping F (R U)
resolve-≮:-⇒ {F} {R} {U} R≮:never FR≮:U | Left F≮:R⇒U = F≮:R⇒U
resolve-≮:-⇒ {F} {R} {U} R≮:never FR≮:U | Right F<:R⇒U = CONTRADICTION (<:-impl-¬≮: (resolve-<:-⇒ R≮:never F<:R⇒U) FR≮:U)

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@ -9,7 +9,7 @@ open import FFI.Data.Maybe using (Maybe; just; nothing)
open import Luau.Heap using (Heap; Object; function_is_end; defn; alloc; ok; next; lookup-not-allocated) renaming (_≡_⊕_↦_ to _≡ᴴ_⊕_↦_; _[_] to _[_]ᴴ; to ∅ᴴ)
open import Luau.StrictMode using (Warningᴱ; Warningᴮ; Warningᴼ; Warningᴴ; UnallocatedAddress; UnboundVariable; FunctionCallMismatch; app₁; app₂; BinOpMismatch₁; BinOpMismatch₂; bin₁; bin₂; BlockMismatch; block₁; return; LocalVarMismatch; local₁; local₂; FunctionDefnMismatch; function₁; function₂; heap; expr; block; addr)
open import Luau.Substitution using (_[_/_]ᴮ; _[_/_]ᴱ; _[_/_]ᴮunless_; var_[_/_]ᴱwhenever_)
open import Luau.Subtyping using (_≮:_; witness; unknown; never; scalar; function; scalar-function; scalar-function-ok; scalar-function-err; scalar-scalar; function-scalar; function-ok; function-err; left; right; _,_; Tree; Language; ¬Language)
open import Luau.Subtyping using (_<:_; _≮:_; witness; unknown; never; scalar; function; scalar-function; scalar-function-ok; scalar-function-err; scalar-scalar; function-scalar; function-ok; function-err; left; right; _,_; Tree; Language; ¬Language)
open import Luau.Syntax using (Expr; yes; var; val; var_∈_; _⟨_⟩∈_; _$_; addr; number; bool; string; binexp; nil; function_is_end; block_is_end; done; return; local_←_; _∙_; fun; arg; name; ==; ~=)
open import Luau.FunctionTypes using (src; tgt)
open import Luau.Type using (Type; nil; number; boolean; string; _⇒_; never; unknown; _∩_; __; _≡ᵀ_; _≡ᴹᵀ_)
@ -26,7 +26,7 @@ open import Properties.Functions using (_∘_)
open import Properties.DecSubtyping using (dec-subtyping)
open import Properties.Subtyping using (unknown-≮:; ≡-trans-≮:; ≮:-trans-≡; ≮:-trans; ≮:-refl; scalar-≢-impl-≮:; function-≮:-scalar; scalar-≮:-function; function-≮:-never; unknown-≮:-scalar; scalar-≮:-never; unknown-≮:-never)
open import Properties.FunctionTypes using (src-unknown-≮:; unknown-src-≮:)
open import Properties.ResolveOverloads using (resolve; <:-resolve)
open import Properties.ResolveOverloads using (resolve; <:-resolve; resolve-≮:-⇒)
open import Properties.Subtyping using (unknown-≮:; ≡-trans-≮:; ≮:-trans-≡; ≮:-trans; <:-trans-≮:; ≮:-refl; scalar-≢-impl-≮:; function-≮:-scalar; scalar-≮:-function; function-≮:-never; unknown-≮:-scalar; scalar-≮:-never; unknown-≮:-never)
open import Properties.TypeCheck using (typeOfᴼ; typeOfᴹᴼ; typeOfⱽ; typeOfᴱ; typeOfᴮ; typeCheckᴱ; typeCheckᴮ; typeCheckᴼ; typeCheckᴴ)
open import Luau.OpSem using (_⟦_⟧_⟶_; _⊢_⟶*_⊣_; _⊢_⟶ᴮ_⊣_; _⊢_⟶ᴱ_⊣_; app₁; app₂; function; beta; return; block; done; local; subst; binOp₀; binOp₁; binOp₂; refl; step; +; -; *; /; <; >; ==; ~=; <=; >=; ··)
@ -37,7 +37,6 @@ open import Luau.RuntimeType using (RuntimeType; valueType; number; string; bool
postulate
resolve⁻¹ : Type Type Type
resolve-≮:-⇒ : {F V U} (resolve F V ≮: U) (F ≮: (V U))
⇒-≮:-resolve : {F V U} (F ≮: (V U)) (resolve F V ≮: U)
⇒-≮:-resolve⁻¹ : {F V U} (F ≮: (V U)) (V ≮: resolve⁻¹ F U)
resolve⁻¹-≮:-⇒ : {F V U} (V ≮: resolve⁻¹ F U) (F ≮: (V U))
@ -87,7 +86,7 @@ heap-weakeningᴱ Γ H (val (addr a)) (snoc {a = b} q) p | no r = ≡-trans-≮:
heap-weakeningᴱ Γ H (val (number x)) h p = p
heap-weakeningᴱ Γ H (val (bool x)) h p = p
heap-weakeningᴱ Γ H (val (string x)) h p = p
heap-weakeningᴱ Γ H (M $ N) h p = ⇒-≮:-resolve (resolve⁻¹-≮:-⇒ (heap-weakeningᴱ Γ H N h (⇒-≮:-resolve⁻¹ (heap-weakeningᴱ Γ H M h (resolve-≮:-⇒ p)))))
heap-weakeningᴱ Γ H (M $ N) h p = ⇒-≮:-resolve (resolve⁻¹-≮:-⇒ (heap-weakeningᴱ Γ H N h (⇒-≮:-resolve⁻¹ (heap-weakeningᴱ Γ H M h (resolve-≮:-⇒ ? p)))))
heap-weakeningᴱ Γ H (function f var x T ⟩∈ U is B end) h p = p
heap-weakeningᴱ Γ H (block var b T is B end) h p = p
heap-weakeningᴱ Γ H (binexp M op N) h p = p
@ -108,7 +107,7 @@ substitutivityᴮ-unless-no : ∀ {Γ Γ′ T V} H B v x y (r : x ≢ y) → (Γ
substitutivityᴱ H (var y) v x p = substitutivityᴱ-whenever H v x y (x ≡ⱽ y) p
substitutivityᴱ H (val w) v x p = Left p
substitutivityᴱ H (binexp M op N) v x p = Left p
substitutivityᴱ H (M $ N) v x p with substitutivityᴱ H M v x (resolve-≮:-⇒ p)
substitutivityᴱ H (M $ N) v x p with substitutivityᴱ H M v x (resolve-≮:-⇒ ? p)
substitutivityᴱ H (M $ N) v x p | Left q with substitutivityᴱ H N v x (⇒-≮:-resolve⁻¹ q)
substitutivityᴱ H (M $ N) v x p | Left q | Left r = Left (⇒-≮:-resolve (resolve⁻¹-≮:-⇒ r))
substitutivityᴱ H (M $ N) v x p | Left q | Right r = Right r
@ -143,13 +142,13 @@ binOpPreservation H (·· v w) = refl
reflect-subtypingᴱ : H M {H M T} (H M ⟶ᴱ M H) (typeOfᴱ H M ≮: T) Either (typeOfᴱ H M ≮: T) (Warningᴱ H (typeCheckᴱ H M))
reflect-subtypingᴮ : H B {H B T} (H B ⟶ᴮ B H) (typeOfᴮ H B ≮: T) Either (typeOfᴮ H B ≮: T) (Warningᴮ H (typeCheckᴮ H B))
reflect-subtypingᴱ H (M $ N) (app₁ s) p with reflect-subtypingᴱ H M s (resolve-≮:-⇒ p)
reflect-subtypingᴱ H (M $ N) (app₁ s) p with reflect-subtypingᴱ H M s (resolve-≮:-⇒ ? p)
reflect-subtypingᴱ H (M $ N) (app₁ s) p | Left q = Left (⇒-≮:-resolve (resolve⁻¹-≮:-⇒ (heap-weakeningᴱ H N (rednᴱ⊑ s) (⇒-≮:-resolve⁻¹ q))))
reflect-subtypingᴱ H (M $ N) (app₁ s) p | Right W = Right (app₁ W)
reflect-subtypingᴱ H (M $ N) (app₂ v s) p with reflect-subtypingᴱ H N s (⇒-≮:-resolve⁻¹ (heap-weakeningᴱ H M (rednᴱ⊑ s) (resolve-≮:-⇒ p)))
reflect-subtypingᴱ H (M $ N) (app₂ v s) p with reflect-subtypingᴱ H N s (⇒-≮:-resolve⁻¹ (heap-weakeningᴱ H M (rednᴱ⊑ s) (resolve-≮:-⇒ ? p)))
reflect-subtypingᴱ H (M $ N) (app₂ v s) p | Left q = Left (⇒-≮:-resolve (resolve⁻¹-≮:-⇒ q))
reflect-subtypingᴱ H (M $ N) (app₂ v s) p | Right W = Right (app₂ W)
reflect-subtypingᴱ H (M $ N) {T = T} (beta (function f var y S ⟩∈ U is B end) v refl q) p = Left (≡-trans-≮: (cong (λ F resolve F (typeOfᴱ H N)) (cong orUnknown (cong typeOfᴹᴼ q))) (<:-trans-≮: (<:-resolve {typeOfᴱ H N}) p))
reflect-subtypingᴱ H (M $ N) {T = T} (beta (function f var y S ⟩∈ U is B end) v refl q) p = Left (≡-trans-≮: (cong (λ F resolve F (typeOfᴱ H N)) (cong orUnknown (cong typeOfᴹᴼ q))) (<:-trans-≮: (<:-resolve {typeOfᴱ H N} {S} {U}) p))
reflect-subtypingᴱ H (function f var x T ⟩∈ U is B end) (function a defn) p = Left p
reflect-subtypingᴱ H (block var b T is B end) (block s) p = Left p
reflect-subtypingᴱ H (block var b T is return (val v) B end) (return v) p = mapR BlockMismatch (swapLR (≮:-trans p))

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@ -337,6 +337,9 @@ never-≮: (witness t p q) = witness t p never
unknown-≮:-never : (unknown ≮: never)
unknown-≮:-never = witness (scalar nil) unknown never
unknown-≮:-function : {S T} (unknown ≮: (S T))
unknown-≮:-function = witness (scalar nil) unknown (function-scalar nil)
function-≮:-never : {T U} ((T U) ≮: never)
function-≮:-never = witness function function never

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@ -233,6 +233,9 @@ ov-<: F here p = p
ov-<: (F G) (left o) p = <:-trans <:-∩-left (ov-<: F o p)
ov-<: (F G) (right o) p = <:-trans <:-∩-right (ov-<: G o p)
<:ᵒ-impl-<: : {F S T} FunType F F <:ᵒ (S T) F <: (S T)
<:ᵒ-impl-<: F (defn o o₁ o₂) = ov-<: F o (<:-function o₁ o₂)
⊂:-overloads-left : {F G} Overloads F ⊂: Overloads (F G)
:-overloads-left p = just (left p)