❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t
PP❙✴πr2
✷✶st ▼❛r❝❤ ✷✵✶✹
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✶ ✴ ✹✶
t r rs - - PowerPoint PPT Presentation
t r rs Prrr Prt PP r 2 st r Prrr Prt PP r 2
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t
PP❙✴πr2
✷✶st ▼❛r❝❤ ✷✵✶✹
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✶ ✴ ✹✶
❈❛t❛❝❧②s♠✿ ●ö❞❡❧✬s ✐♥❝♦♠♣❧❡t❡♥❡ss t❤❡♦r❡♠ ✭✶✾✸✶✮ ❲❡ ❞♦ ♥♦t ✜❣❤t ❛❧✐❡♥❛t✐♦♥ ✇✐t❤ ❛♥ ❛❧✐❡♥❛t❡❞ ❧♦❣✐❝✳ ❏✉st✐❢②✐♥❣ ❛r✐t❤♠❡t✐❝ ❞✐✛❡r❡♥t❧② ✳✳✳ ■♥t✉✐t✐♦♥✐st✐❝ ❧♦❣✐❝✦
❉♦✉❜❧❡✲♥❡❣❛t✐♦♥ tr❛♥s❧❛t✐♦♥ ✭✶✾✸✸✮ ❉✐❛❧❡❝t✐❝❛ ✭✸✵✬s✱ ♣✉❜❧✐s❤❡❞ ✐♥ ✶✾✺✽✮
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✷ ✴ ✹✶
❈❛t❛❝❧②s♠✿ ●ö❞❡❧✬s ✐♥❝♦♠♣❧❡t❡♥❡ss t❤❡♦r❡♠ ✭✶✾✸✶✮ ❲❡ ❞♦ ♥♦t ✜❣❤t ❛❧✐❡♥❛t✐♦♥ ✇✐t❤ ❛♥ ❛❧✐❡♥❛t❡❞ ❧♦❣✐❝✳ ❏✉st✐❢②✐♥❣ ❛r✐t❤♠❡t✐❝ ❞✐✛❡r❡♥t❧② ✳✳✳ ■♥t✉✐t✐♦♥✐st✐❝ ❧♦❣✐❝✦
❉♦✉❜❧❡✲♥❡❣❛t✐♦♥ tr❛♥s❧❛t✐♦♥ ✭✶✾✸✸✮ ❉✐❛❧❡❝t✐❝❛ ✭✸✵✬s✱ ♣✉❜❧✐s❤❡❞ ✐♥ ✶✾✺✽✮
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✷ ✴ ✹✶
❈❛t❛❝❧②s♠✿ ●ö❞❡❧✬s ✐♥❝♦♠♣❧❡t❡♥❡ss t❤❡♦r❡♠ ✭✶✾✸✶✮ ❲❡ ❞♦ ♥♦t ✜❣❤t ❛❧✐❡♥❛t✐♦♥ ✇✐t❤ ❛♥ ❛❧✐❡♥❛t❡❞ ❧♦❣✐❝✳ ❏✉st✐❢②✐♥❣ ❛r✐t❤♠❡t✐❝ ❞✐✛❡r❡♥t❧② ✳✳✳ ■♥t✉✐t✐♦♥✐st✐❝ ❧♦❣✐❝✦
❉♦✉❜❧❡✲♥❡❣❛t✐♦♥ tr❛♥s❧❛t✐♦♥ ✭✶✾✸✸✮ ❉✐❛❧❡❝t✐❝❛ ✭✸✵✬s✱ ♣✉❜❧✐s❤❡❞ ✐♥ ✶✾✺✽✮
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✷ ✴ ✹✶
✶
❍✐st♦r✐❝❛❧ ♣r❡s❡♥t❛t✐♦♥
✷
❆ st❡♣ ✐♥t♦ ♠♦❞❡r♥✐t②
✸
❊♥t❡rs ▲✐♥❡❛r ▲♦❣✐❝
✹
❆ s②♥t❛❝t✐❝ ♣r❡s❡♥t❛t✐♦♥
✺
❚♦✇❛r❞s CCω
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✸ ✴ ✹✶
❲❤❛t ✐s ❉✐❛❧❡❝t✐❝❛❄ ❆ tr❛♥s❧❛t✐♦♥ ❢r♦♠ ❍❆ ✐♥t♦ ❍❆ ❚❤❛t ♣r❡s❡r✈❡s ✐♥t✉✐t✐♦♥✐st✐❝ ❝♦♥t❡♥t ❇✉t ♦✛❡rs t✇♦ s❡♠✐✲❝❧❛ss✐❝❛❧ ♣r✐♥❝✐♣❧❡s✿ ▼P ■P
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✹ ✴ ✹✶
❲❤❛t ✐s ❉✐❛❧❡❝t✐❝❛❄ ❆ tr❛♥s❧❛t✐♦♥ ❢r♦♠ ❍❆ ✐♥t♦ ❍❆ω ❚❤❛t ♣r❡s❡r✈❡s ✐♥t✉✐t✐♦♥✐st✐❝ ❝♦♥t❡♥t ❇✉t ♦✛❡rs t✇♦ s❡♠✐✲❝❧❛ss✐❝❛❧ ♣r✐♥❝✐♣❧❡s✿ ▼P ■P
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✹ ✴ ✹✶
❲❤❛t ✐s ❉✐❛❧❡❝t✐❝❛❄ ❆ tr❛♥s❧❛t✐♦♥ ❢r♦♠ ❍❆ ✐♥t♦ ❍❆ω ❚❤❛t ♣r❡s❡r✈❡s ✐♥t✉✐t✐♦♥✐st✐❝ ❝♦♥t❡♥t ❇✉t ♦✛❡rs t✇♦ s❡♠✐✲❝❧❛ss✐❝❛❧ ♣r✐♥❝✐♣❧❡s✿ ¬(∀n ∈ N. ¬P n) ▼P ∃n ∈ N. P n (∀n ∈ N. P n) → ∃m ∈ N. Q m ■P ∃m ∈ N. (∀n ∈ N. P n) → Q m
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✹ ✴ ✹✶
❋♦r t❤❡ s❛❦❡ ♦❢ ❡①❤❛✉st✐✈✐t②✱ ✇❡✬❧❧ t❛❦❡ ❛ ❣❧✐♠♣s❡ ❛t t❤❡ ❤✐st♦r✐❝❛❧ ♣r❡s❡♥t❛t✐♦♥ ♦❢ ❉✐❛❧❡❝t✐❝❛✳ ❲❛r♥✐♥❣✦ ❉✉st② ❧♦❣✐❝ ✐♥s✐❞❡ ❚r❛♥s❧❛t✐♦♥ ❛❝t✐♥❣ ♦♥ ❢♦r♠✉❧æ Pr❡✈❛❧❡♥❝❡ ♦❢ ♥❡❣❛t✐✈❡ ❝♦♥♥❡❝t✐✈❡s ❋✐rst✲♦r❞❡r ❧♦❣✐❝ ▲♦ts ♦❢ ❛r✐t❤♠❡t✐❝ ❡♥❝♦❞✐♥❣ ❉♦❡s ♥♦t ♣r❡s❡r✈❡ ✲r❡❞✉❝t✐♦♥
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✺ ✴ ✹✶
❋♦r t❤❡ s❛❦❡ ♦❢ ❡①❤❛✉st✐✈✐t②✱ ✇❡✬❧❧ t❛❦❡ ❛ ❣❧✐♠♣s❡ ❛t t❤❡ ❤✐st♦r✐❝❛❧ ♣r❡s❡♥t❛t✐♦♥ ♦❢ ❉✐❛❧❡❝t✐❝❛✳ ❲❛r♥✐♥❣✦ ❉✉st② ❧♦❣✐❝ ✐♥s✐❞❡ ❚r❛♥s❧❛t✐♦♥ ❛❝t✐♥❣ ♦♥ ❢♦r♠✉❧æ Pr❡✈❛❧❡♥❝❡ ♦❢ ♥❡❣❛t✐✈❡ ❝♦♥♥❡❝t✐✈❡s ❋✐rst✲♦r❞❡r ❧♦❣✐❝ ▲♦ts ♦❢ ❛r✐t❤♠❡t✐❝ ❡♥❝♦❞✐♥❣ ❉♦❡s ♥♦t ♣r❡s❡r✈❡ β✲r❡❞✉❝t✐♦♥
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✺ ✴ ✹✶
❉✐❛❧❡❝t✐❝❛✱ ❉❛✇♥ ♦❢ ❈✉rr②✲❍♦✇❛r❞✿ ⊢ A → ⊢ AD ≡ ∃
u, x]
A ∧ B ∃ u v. ∀ x y. AD[ u, x] ∧ BD[ v, y] A ∨ B ∃ u v b. ∀ x y. (b = 0 ∧ AD[ u, x]) ∨ (b = 1 ∧ BD[ v, y]) A → B ∃ ϕ ψ. ∀ u y. AD[ u, ψ( u, y)] → BD[ ϕ( u), y] ∀n. A[n] ∃ ϕ. ∀ x n. AD[ ϕ(n), x, n] ∃n. A[n] ∃ u n. ∀ x. AD[ u, n, x]
❙♦✉♥❞ tr❛♥s❧❛t✐♦♥✱ ❜❧❛❤ ❜❧❛❤ ❜❧❛❤✳
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✻ ✴ ✹✶
▲❡t ✉s ❢♦r❣❡t t❤❡ ✺✵✬s✱ ❛♥❞ r❛t❤❡r ❥✉♠♣ ❞✐r❡❝t❧② t♦ t❤❡ ✾✵✬s✳ ❚❛❦❡ s❡r✐♦✉s❧② t❤❡ ❝♦♠♣✉t❛t✐♦♥❛❧ ❝♦♥t❡♥t ❉✐❛❧❡❝t✐❝❛ ❛s ❛ t②♣❡❞ ♦❜❥❡❝t ❲♦r❦s ♦❢ ❉❡ P❛✐✈❛✱ ❍②❧❛♥❞✱ ❡t❝✳
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✼ ✴ ✹✶
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✽ ✴ ✹✶
❆ ♣r♦♦❢ ⊢ u : A ✐s ❛ t❡r♠ ⊢ u : W(A) s✉❝❤ t❤❛t✿ ∀x : C(A). u ⊥A x ■❢ ✇❡ ✇✐s❤ t♦ ♣✉t ♠♦r❡ t②♣❡s ✐♥ t❤❡r❡✿
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✾ ✴ ✹✶
❆ ♣r♦♦❢ ⊢ u : A ✐s ❛ t❡r♠ ⊢ u : W(A) s✉❝❤ t❤❛t✿ ∀x : C(A). u ⊥A x ■❢ ✇❡ ✇✐s❤ t♦ ♣✉t ♠♦r❡ t②♣❡s ✐♥ t❤❡r❡✿
W C A ∧ B ∃ u v. ∀ x y. A × B W(A) × W(B) C(A) × C(B) A ∨ B ∃b u v. ∀ x y. A + B bool × W(A) × W(B) C(A) × C(B) A → B ∃ ϕ ψ. ∀ u y. A → B W(A) → W(B) C(B) → W(A) → C(A) W(A) × C(B)
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✾ ✴ ✹✶
❆ ♣r♦♦❢ ⊢ u : A ✐s ❛ t❡r♠ ⊢ u : W(A) s✉❝❤ t❤❛t✿ ∀x : C(A). u ⊥A x ■❢ ✇❡ ✇✐s❤ t♦ ♣✉t ♠♦r❡ t②♣❡s ✐♥ t❤❡r❡✿
W C A ∧ B ∃ u v. ∀ x y. A × B W(A) × W(B) C(A) × C(B) A ∨ B ∃b u v. ∀ x y. A + B bool × W(A) × W(B) C(A) × C(B) A → B ∃ ϕ ψ. ∀ u y. A → B W(A) → W(B) C(B) → W(A) → C(A) W(A) × C(B)
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✾ ✴ ✹✶
❇✉t✱ ❣r❛♥❞♠♦t❤❡r✱ ❤♦✇ ❢❛♠✐❧✐❛r ②♦✉ ❧♦♦❦✳✳✳ ❈❧❛ss✐❝❛❧ r❡❛❧✐③❛❜✐❧✐t②✿ ♣r♦♦❢s ✱ st❛❝❦s ❉♦✉❜❧❡✲♦rt❤♦❣♦♥❛❧✐t② ❜❛s❡❞ ♠♦❞❡❧s ❉♦✉❜❧❡✲❣❧✉❡✐♥❣ ❘❡❞✉❝✐❜✐❧✐t② ❝❛♥❞✐❞❛t❡s
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✶✵ ✴ ✹✶
❇✉t✱ ❣r❛♥❞♠♦t❤❡r✱ ❤♦✇ ❢❛♠✐❧✐❛r ②♦✉ ❧♦♦❦✳✳✳ ❈❧❛ss✐❝❛❧ r❡❛❧✐③❛❜✐❧✐t②✿ W(A) ♣r♦♦❢s |A|✱ C(A) st❛❝❦s ||A|| ❉♦✉❜❧❡✲♦rt❤♦❣♦♥❛❧✐t② ❜❛s❡❞ ♠♦❞❡❧s ❉♦✉❜❧❡✲❣❧✉❡✐♥❣ ❘❡❞✉❝✐❜✐❧✐t② ❝❛♥❞✐❞❛t❡s . . .
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✶✵ ✴ ✹✶
❲❡ ❝♦✉❧❞ ❣✐✈❡ ❛ ❝♦♠♣✉t❛t✐♦♥❛❧ ❝♦♥t❡♥t r✐❣❤t ♥♦✇ ❇✉t ✐t ✇♦✉❧❞ ❜❡ ❛❞✲❤♦❝✱ ✐♥❤❡r✐t✐♥❣ ❢r♦♠ t❤❡ ❡♥❝♦❞✐♥❣s ♦❢ ❉✐❛❧❡❝t✐❝❛ ▲❡t ✉s ✉s❡ ♦✉r ♦✉r ❢❛✈♦r✐t❡ t♦♦❧✿ ▲✐♥❡❛r ▲♦❣✐❝✦
❆ ❣❡♥✉✐♥❡ ❡①♣♦♥❡♥t✐❛❧✦ ❲✐t❤ r❡❛❧ ❝❤✉♥❦s ♦❢ s✉♠ t②♣❡s✦
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✶✶ ✴ ✹✶
❲❡ ❝♦✉❧❞ ❣✐✈❡ ❛ ❝♦♠♣✉t❛t✐♦♥❛❧ ❝♦♥t❡♥t r✐❣❤t ♥♦✇ ❇✉t ✐t ✇♦✉❧❞ ❜❡ ❛❞✲❤♦❝✱ ✐♥❤❡r✐t✐♥❣ ❢r♦♠ t❤❡ ❡♥❝♦❞✐♥❣s ♦❢ ❉✐❛❧❡❝t✐❝❛ ▲❡t ✉s ✉s❡ ♦✉r ♦✉r ❢❛✈♦r✐t❡ t♦♦❧✿ ▲✐♥❡❛r ▲♦❣✐❝✦
❆ ❣❡♥✉✐♥❡ ❡①♣♦♥❡♥t✐❛❧✦ ❲✐t❤ r❡❛❧ ❝❤✉♥❦s ♦❢ s✉♠ t②♣❡s✦
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✶✶ ✴ ✹✶
❆s ❢♦r❡❝❛st❡❞ ♦♥ t❤❡ ♣r❡✈✐♦✉s s❧✐❞❡✱ ✇❡ ❡ss❡♥t✐❛❧❧② ❛♣♣❧② t❤❡ ❢♦❧❧♦✇✐♥❣ ♠♦❞✐✜❝❛t✐♦♥s✿ ■♥tr♦❞✉❝t✐♦♥ ♦❢ ❞✉❛❧✐t② ✇✐t❤ s✉♠ t②♣❡s ❈❛❧❧✲❜②✲♥❛♠❡ ❞❡❝♦♠♣♦s✐t✐♦♥ ♦❢ t❤❡ ❛rr♦✇✿ A → B ≡ !A ⊸ B ◆♦✇ ✇❡ ✇✐❧❧ ❜❡ tr❛♥s❧❛t✐♥❣ ❢♦r♠✉❧æ ✐♥t♦ ♦♥❡s✳
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✶✷ ✴ ✹✶
❆s ❢♦r❡❝❛st❡❞ ♦♥ t❤❡ ♣r❡✈✐♦✉s s❧✐❞❡✱ ✇❡ ❡ss❡♥t✐❛❧❧② ❛♣♣❧② t❤❡ ❢♦❧❧♦✇✐♥❣ ♠♦❞✐✜❝❛t✐♦♥s✿ ■♥tr♦❞✉❝t✐♦♥ ♦❢ ❞✉❛❧✐t② ✇✐t❤ s✉♠ t②♣❡s ❈❛❧❧✲❜②✲♥❛♠❡ ❞❡❝♦♠♣♦s✐t✐♦♥ ♦❢ t❤❡ ❛rr♦✇✿ A → B ≡ !A ⊸ B ◆♦✇ ✇❡ ✇✐❧❧ ❜❡ tr❛♥s❧❛t✐♥❣ LL ❢♦r♠✉❧æ ✐♥t♦ LJ ♦♥❡s✳
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✶✷ ✴ ✹✶
❲❡ ✇✐❧❧ ❜❡ ✐♥t❡r♣r❡t✐♥❣ t❤❡ ❢♦r♠✉❧æ ♦❢ ❧✐♥❡❛r ❧♦❣✐❝✿ A, B ::= A ⊗ B | A ` B | A ⊕ B | A & B | !A | ?A ■t ✐s t❤❡r❡❢♦r❡ s✉✣❝✐❡♥t t♦ ❞❡✜♥❡ W(A)✱ C(A) ❛♥❞ ⊥A ❢♦r ❡❛❝❤ A✱ ✇❤❡r❡✿ ⊥A ⊆ W(A) × C(A)
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✶✸ ✴ ✹✶
❚❛❦✐♥❣ ✐♥s♣✐r❛t✐♦♥ ❢r♦♠ t❤❡ ❞♦✉❜❧❡✲♦rt❤♦❣♦♥❛❧✐t② ♠♦❞❡❧s✱ ✇❡ r❡q✉✐r❡✿ W(A⊥) ≡ C(A) ❛♥❞ ❝♦♥✈❡rs❡❧②❀ ■t ✐s s✉✣❝✐❡♥t t♦ ❞❡✜♥❡ ♦✉r str✉❝t✉r❡s ♦♥ ♣♦s✐t✐✈❡ t②♣❡s ❲❡ ✇✐❧❧ ❣❡t t❤❡♠ ❢♦r ❞✉❛❧ ❝♦♥♥❡❝t✐✈❡s✳✳✳ ❜② ❞✉❛❧✐t②✳ ❲❡ ❞❡✜♥❡ t❤❡r❡❢♦r❡✿
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✶✹ ✴ ✹✶
❚❛❦✐♥❣ ✐♥s♣✐r❛t✐♦♥ ❢r♦♠ t❤❡ ❞♦✉❜❧❡✲♦rt❤♦❣♦♥❛❧✐t② ♠♦❞❡❧s✱ ✇❡ r❡q✉✐r❡✿ W(A⊥) ≡ C(A) ❛♥❞ ❝♦♥✈❡rs❡❧②❀ ■t ✐s s✉✣❝✐❡♥t t♦ ❞❡✜♥❡ ♦✉r str✉❝t✉r❡s ♦♥ ♣♦s✐t✐✈❡ t②♣❡s ❲❡ ✇✐❧❧ ❣❡t t❤❡♠ ❢♦r ❞✉❛❧ ❝♦♥♥❡❝t✐✈❡s✳✳✳ ❜② ❞✉❛❧✐t②✳ ❲❡ ❞❡✜♥❡ t❤❡r❡❢♦r❡✿ u ⊥A x x ⊥A⊥ u
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✶✹ ✴ ✹✶
W C A × B W(A) × W(B) C(A) × C(B) A & B W(A) × W(B) C(A) + C(B) A + B bool × W(A) × W(B) C(A) × C(B) A ⊕ B W(A) + W(B) C(A) × C(B)
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✶✺ ✴ ✹✶
W C A × B W(A) × W(B) C(A) × C(B) A & B W(A) × W(B) C(A) + C(B) A + B bool × W(A) × W(B) C(A) × C(B) A ⊕ B W(A) + W(B) C(A) × C(B) v ⊥A z2 inr v ⊥A⊕B (z1, z2) u ⊥A z1 inl u ⊥A⊕B (z1, z2)
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✶✺ ✴ ✹✶
W C A → B
C(B) → W(A) → C(A) C(A) × C(B) A ⊸ B W(A) → W(B) C(B) → C(A) W(A) × C(B) !A W(A) W(A) → C(A)
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✶✻ ✴ ✹✶
W C A → B
C(B) → W(A) → C(A) C(A) × C(B) A ⊸ B W(A) → W(B) C(B) → C(A) W(A) × C(B) !A W(A) W(A) → C(A) u ⊥A ψ y → ϕ u ⊥B y (ϕ, ψ) ⊥A⊸B (u, y) u ⊥A z u u ⊥!A z
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✶✻ ✴ ✹✶
❚❤❡ ✐♥t❡r♣r❡t❛t✐♦♥ ♦❢ ❛rr♦✇ ❢♦r❝❡s ✐ts r❡✈❡rs✐❜✐❧✐t②✿ A ⊸ B ∼ = B⊥ ⊸ A⊥
▲✐❦❡ t❤❡ t✇♦✲✇❛② ♣r♦♦❢♥❡t ✇✐r❡s
❚❤❡ ❜❛♥❣ ❝♦♥♥❡❝t✐✈❡ ✐s ❛ s❤✐❢t ✿
❖♣♣♦♥❡♥t ♠❛② ✇❛✐t ❢♦r t❤❡ ♣❧❛②❡r t♦ ♣❧❛② ❛♥❞ ✐♥s♣❡❝t ✐ts ❛♥s✇❡r
❉✉❛❧✐t② ✐s rô❧❡ s✇❛♣♣✐♥❣
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✶✼ ✴ ✹✶
❚❤❡ ✐♥t❡r♣r❡t❛t✐♦♥ ♦❢ ❛rr♦✇ ❢♦r❝❡s ✐ts r❡✈❡rs✐❜✐❧✐t②✿ A ⊸ B ∼ = B⊥ ⊸ A⊥
▲✐❦❡ t❤❡ t✇♦✲✇❛② ♣r♦♦❢♥❡t ✇✐r❡s
❚❤❡ ❜❛♥❣ ❝♦♥♥❡❝t✐✈❡ ✐s ❛ s❤✐❢t ✿
❖♣♣♦♥❡♥t ♠❛② ✇❛✐t ❢♦r t❤❡ ♣❧❛②❡r t♦ ♣❧❛② ❛♥❞ ✐♥s♣❡❝t ✐ts ❛♥s✇❡r
❉✉❛❧✐t② ✐s rô❧❡ s✇❛♣♣✐♥❣
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✶✼ ✴ ✹✶
❲❡✬r❡ ♥♦t ❧✐♥❡❛r ❜② ❝❤❛♥❝❡✳ ■♥❞❡❡❞✱ ✐♥ ❉✐❛❧❡❝t✐❝❛✱ ✇❡ ❞♦ ♥♦t ❤❛✈❡ t❤❡ ❢♦❧❧♦✇✐♥❣ ♠♦r♣❤✐s♠s✿
✶
❍❡♥❝❡ ✇❡ ❤❛✈❡ tr✉❡ ❧✐♥❡❛r ❝♦♥str❛✐♥ts✦✷
✶❆ss✉♠✐♥❣ ✇❡✬✈❡ ❞❡✜♥❡❞ 1✳ ✷▼❛② ❝♦♥t❛✐♥ ♥✉ts✳ P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✶✽ ✴ ✹✶
❲❡✬r❡ ♥♦t ❧✐♥❡❛r ❜② ❝❤❛♥❝❡✳ ■♥❞❡❡❞✱ ✐♥ ❉✐❛❧❡❝t✐❝❛✱ ✇❡ ❞♦ ♥♦t ❤❛✈❡ t❤❡ ❢♦❧❧♦✇✐♥❣ ♠♦r♣❤✐s♠s✿ ⊢ A ⊸ 1✶ ⊢ A ⊸ A ⊗ A ❍❡♥❝❡ ✇❡ ❤❛✈❡ tr✉❡ ❧✐♥❡❛r ❝♦♥str❛✐♥ts✦✷
✶❆ss✉♠✐♥❣ ✇❡✬✈❡ ❞❡✜♥❡❞ 1✳ ✷▼❛② ❝♦♥t❛✐♥ ♥✉ts✳ P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✶✽ ✴ ✹✶
❲❡✬r❡ ♥♦✇ tr②✐♥❣ t♦ tr❛♥s❧❛t❡ t❤❡ λ✲❝❛❧❝✉❧✉s t❤r♦✉❣❤ ❉✐❛❧❡❝t✐❝❛✳ ❋✐rst t❤r♦✉❣❤ t❤❡ ❝❛❧❧✲❜②✲♥❛♠❡ ❧✐♥❡❛r ❞❡❝♦♠♣♦s✐t✐♦♥ ✐♥t♦ ▲▲❀ ❚❤❡♥ ✐♥t♦ ▲❏ ✇✐t❤ t❤❡ ❧✐♥❡❛r ❉✐❛❧❡❝t✐❝❛✳
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✶✾ ✴ ✹✶
❲❡ r❡❝❛❧❧ ❤❡r❡ t❤❡ ❝❛❧❧✲❜②✲♥❛♠❡ tr❛♥s❧❛t✐♦♥ ♦❢ t❤❡ λ✲❝❛❧❝✉❧✉s ✐♥t♦ ▲▲✿ [ [A → B] ] ≡ ![ [A] ] ⊸ [ [B] ] [ [A × B] ] ≡ ![ [A] ] ⊗ ![ [B] ] [ [A + B] ] ≡ ![ [A] ] ⊕ ![ [B] ] [ [Γ ⊢ A] ] ≡
[Γ] ] ⊢ [ [A] ]
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✷✵ ✴ ✹✶
■♥ ♦r❞❡r t♦ ✐♥t❡r♣r❡t t❤❡ λ✲❝❛❧❝✉❧✉s✱ ✇❡ ♥❡❡❞ t❤❡ ❢♦❧❧♦✇✐♥❣✿
❉✉♠♠② t❡r♠
❋♦r ❛❧❧ t②♣❡ A✱ t❤❡r❡ ❡①✐sts ⊢ ∅A : W(A)✳
❉❡❝✐❞❛❜✐❧✐t② ♦❢ t❤❡ ♦rt❤♦❣♦♥❛❧✐t②
❚❤❡ ⊥A r❡❧❛t✐♦♥ ✐s ❞❡❝✐❞❛❜❧❡✳ ■♥ ♣❛rt✐❝✉❧❛r✱ t❤❡r❡ ♠✉st ❡①✐st s♦♠❡ λ✲t❡r♠ @A : W(A) → W(A) → C(A) → W(A) ✇✐t❤ t❤❡ ❢♦❧❧♦✇✐♥❣ ❜❡❤❛✈✐♦✉r✿ u1@A
x u2 ∼
= if u1 ⊥A x then u2 else u1
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✷✶ ✴ ✹✶
■❢ ✇❡ ✇❡r❡ t♦ ✉s❡ t❤❡ tr❛♥s❧❛t✐♦♥ ❛s ✐s✱ ✇❡ ✇♦✉❧❞ ❜✉♠♣ ✉♣ ✐♥t♦ ❛♥ ✉♥❜❡❛r❛❜❧❡ ❜✉r❡❛✉❝r❛❝②✳ ■♥st❡❛❞✱ ✇❡ ❛r❡ ❣♦✐♥❣ t♦ ✉s❡ t❤❡ ❢♦❧❧♦✇✐♥❣ ✐s♦♠♦r♣❤✐s♠✳ [ [x1 : Γ1, . . . xn : Γn ⊢ t : A] ] ∼ = W(Γ) → W(A) C(A) → C(Γ1) ✳ ✳ ✳ C(A) → C(Γn) ❲❤✐❝❤ r❡s✉❧ts ✐♥ t❤❡ ❢♦❧❧♦✇✐♥❣ tr❛♥s❧❛t✐♦♥s✿ ✳ ✳ ✳
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✷✷ ✴ ✹✶
■❢ ✇❡ ✇❡r❡ t♦ ✉s❡ t❤❡ tr❛♥s❧❛t✐♦♥ ❛s ✐s✱ ✇❡ ✇♦✉❧❞ ❜✉♠♣ ✉♣ ✐♥t♦ ❛♥ ✉♥❜❡❛r❛❜❧❡ ❜✉r❡❛✉❝r❛❝②✳ ■♥st❡❛❞✱ ✇❡ ❛r❡ ❣♦✐♥❣ t♦ ✉s❡ t❤❡ ❢♦❧❧♦✇✐♥❣ ✐s♦♠♦r♣❤✐s♠✳ [ [x1 : Γ1, . . . xn : Γn ⊢ t : A] ] ∼ = W(Γ) → W(A) C(A) → C(Γ1) ✳ ✳ ✳ C(A) → C(Γn) ❲❤✐❝❤ r❡s✉❧ts ✐♥ t❤❡ ❢♦❧❧♦✇✐♥❣ tr❛♥s❧❛t✐♦♥s✿ [ [ x : Γ ⊢ t : A] ] ≡
✳ ✳ ✳
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✷✷ ✴ ✹✶
❋♦r (−)• ✿ x• ≡ x (λx. t)• ≡ λx. t• λπx. tx π (t u)• ≡ (fst t•) u•
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✷✸ ✴ ✹✶
❋♦r tx ✿ xx ≡ λπ. π : C(A) → C(A) yx ≡ λπ. ∅ : C(A) → C(Γi) (λy. t)x ≡ λ(y, π). tx π : W(A) × C(B) → C(Γi) (t u)x ≡ λπ. ux ((snd t•) π u•) @π tx (u•, π) : C(B) → C(Γi)
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✷✹ ✴ ✹✶
❙♦✉♥❞♥❡ss
■❢ ⊢ t : A✱ t❤❡♥ ⊢ [ [t] ] : W(A)✱ ❛♥❞ ✐♥ ❛❞❞✐t✐♦♥✱ ❢♦r ❛❧❧ π : C(A)✱ t ⊥A π✳ ❙❛❞♥❡ss ❚❤❡ tr❛♥s❧❛t✐♦♥ ✐s st✐❧❧ ♥♦t st❛❜❧❡ ❜② ✲r❡❞✉❝t✐♦♥✳
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✷✺ ✴ ✹✶
❙♦✉♥❞♥❡ss
■❢ ⊢ t : A✱ t❤❡♥ ⊢ [ [t] ] : W(A)✱ ❛♥❞ ✐♥ ❛❞❞✐t✐♦♥✱ ❢♦r ❛❧❧ π : C(A)✱ t ⊥A π✳ ❙❛❞♥❡ss ❚❤❡ tr❛♥s❧❛t✐♦♥ ✐s st✐❧❧ ♥♦t st❛❜❧❡ ❜② β✲r❡❞✉❝t✐♦♥✳
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✷✺ ✴ ✹✶
❯s✐♥❣ ∅ ❛♥❞ @ ✐s ❛♥♦t❤❡r ❡♥❝♦❞✐♥❣ ♦❢ ❉✐❛❧❡❝t✐❝❛✳ ❲❡ ✇❛♥t ❧✐sts✦
❛❧♠♦st✳✳✳
❲❡ ❥✉st ❝❤❛♥❣❡✿ ❚❡r♠ ✐♥t❡r♣r❡t❛t✐♦♥ ✐s ❛❧♠♦st ✉♥❝❤❛♥❣❡❞✿
❜❡❝♦♠❡s t❤❡ ❡♠♣t② ❧✐st❀ ❜❡❝♦♠❡s ❝♦♥❝❛t❡♥❛t✐♦♥ ♣❧✉s ❛ ❜✐t ♦❢ ♠♦♥❛❞✐❝ ❜♦✐❧❡r♣❧❛t❡
❲❡ ❞♦ ♥♦t ♥❡❡❞ ♦rt❤♦❣♦♥❛❧✐t② ❛♥②♠♦r❡✳✳✳
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✷✻ ✴ ✹✶
❯s✐♥❣ ∅ ❛♥❞ @ ✐s ❛♥♦t❤❡r ❡♥❝♦❞✐♥❣ ♦❢ ❉✐❛❧❡❝t✐❝❛✳ ❲❡ ✇❛♥t ❧✐sts✦
❛❧♠♦st✳✳✳
❲❡ ❥✉st ❝❤❛♥❣❡✿ C(!A) ≡ W(A) → C(A) C(!A) ≡ W(A) → list C(A) ❚❡r♠ ✐♥t❡r♣r❡t❛t✐♦♥ ✐s ❛❧♠♦st ✉♥❝❤❛♥❣❡❞✿
∅ ❜❡❝♦♠❡s t❤❡ ❡♠♣t② ❧✐st❀ @ ❜❡❝♦♠❡s ❝♦♥❝❛t❡♥❛t✐♦♥ . . . ♣❧✉s ❛ ❜✐t ♦❢ ♠♦♥❛❞✐❝ ❜♦✐❧❡r♣❧❛t❡
❲❡ ❞♦ ♥♦t ♥❡❡❞ ♦rt❤♦❣♦♥❛❧✐t② ❛♥②♠♦r❡✳✳✳
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✷✻ ✴ ✹✶
❚❤✐s ❣✐✈❡s ✉s t❤❡ ❢♦❧❧♦✇✐♥❣ t②♣❡s ❢♦r t❤❡ tr❛♥s❧❛t✐♦♥✿ [ [ x : Γ ⊢ t : A] ] ≡
✳ ✳ ✳
✐s ❝❧❡❛r❧② t❤❡ ❧✐❢t✐♥❣ ♦❢ ❀ ❲❤❛t ♦♥ ❡❛rt❤ ✐s ❄
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✷✼ ✴ ✹✶
❚❤✐s ❣✐✈❡s ✉s t❤❡ ❢♦❧❧♦✇✐♥❣ t②♣❡s ❢♦r t❤❡ tr❛♥s❧❛t✐♦♥✿ [ [ x : Γ ⊢ t : A] ] ≡
✳ ✳ ✳
t• ✐s ❝❧❡❛r❧② t❤❡ ❧✐❢t✐♥❣ ♦❢ t❀ ❲❤❛t ♦♥ ❡❛rt❤ ✐s ❄
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✷✼ ✴ ✹✶
❚❤✐s ❣✐✈❡s ✉s t❤❡ ❢♦❧❧♦✇✐♥❣ t②♣❡s ❢♦r t❤❡ tr❛♥s❧❛t✐♦♥✿ [ [ x : Γ ⊢ t : A] ] ≡
✳ ✳ ✳
t• ✐s ❝❧❡❛r❧② t❤❡ ❧✐❢t✐♥❣ ♦❢ t❀ ❲❤❛t ♦♥ ❡❛rt❤ ✐s txi❄
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✷✼ ✴ ✹✶
❆ s♠❛❧❧ ✐♥t❡r❧✉❞❡ ♦❢ ❛❞✈❡rt✐s❡♠❡♥t ❞❡✜♥✐t✐♦♥s t♦ ✐♥tr♦❞✉❝❡ ②♦✉ t♦ t❤❡ ❑❆▼✳
❈❧♦s✉r❡s ❊♥✈✐r♦♥♠❡♥ts ❙t❛❝❦s Pr♦❝❡ss❡s P✉s❤ P♦♣
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✷✽ ✴ ✹✶
❆ s♠❛❧❧ ✐♥t❡r❧✉❞❡ ♦❢ ❛❞✈❡rt✐s❡♠❡♥t ❞❡✜♥✐t✐♦♥s t♦ ✐♥tr♦❞✉❝❡ ②♦✉ t♦ t❤❡ ❑❆▼✳
❈❧♦s✉r❡s c ::= (t, σ) ❊♥✈✐r♦♥♠❡♥ts σ ::= ∅ | σ + (x := c) ❙t❛❝❦s π ::= ε | c · π Pr♦❝❡ss❡s p ::= c | π P✉s❤ (t u, σ) | π → (t, σ) | (u, σ) · π P♦♣ (λx. t, σ) | c · π → (t, σ + (x := c)) | π
(x, σ + (x := c)) | π → c | π
(x, σ + (y := c)) | π → (x, σ) | π The Krivine Machine™
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✷✽ ✴ ✹✶
▲❡t✿
❛ t❡r♠ x : Γ ⊢ t : A ❛ ❝❧♦s✉r❡ σ ⊢ Γ ❛ st❛❝❦ ⊢ π : A⊥ ✭✐✳❡✳ [ [π] ] : C(A)✮
❚❤❡♥ ✐s t❤❡ ❧✐st ♠❛❞❡ ♦❢ t❤❡ st❛❝❦s ❡♥❝♦✉♥t❡r❡❞ ❜② ✇❤✐❧❡ ❡✈❛❧✉❛t✐♥❣ ✱ ✐✳❡✳ ✳ ✳ ✳ ✳ ✳ ✳ ❖t❤❡r✇✐s❡ s❛✐❞✱ ❉✐❛❧❡❝t✐❝❛ tr❛❝❦s t❤❡ ●r❛❜ r✉❧❡✳
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✷✾ ✴ ✹✶
▲❡t✿
❛ t❡r♠ x : Γ ⊢ t : A ❛ ❝❧♦s✉r❡ σ ⊢ Γ ❛ st❛❝❦ ⊢ π : A⊥ ✭✐✳❡✳ [ [π] ] : C(A)✮
❚❤❡♥ txi π ✐s t❤❡ ❧✐st ♠❛❞❡ ♦❢ t❤❡ st❛❝❦s ❡♥❝♦✉♥t❡r❡❞ ❜② xi ✇❤✐❧❡ ❡✈❛❧✉❛t✐♥❣ (t, σ) | π✱ ✐✳❡✳ (txi{ x := σ}) π = [ρ1; . . . ; ρm] (t, σ) | π − →∗ (xi, σ1) | ρ1 ✳ ✳ ✳ ✳ ✳ ✳ − →∗ (xi, σm) | ρm ❖t❤❡r✇✐s❡ s❛✐❞✱ ❉✐❛❧❡❝t✐❝❛ tr❛❝❦s t❤❡ ●r❛❜ r✉❧❡✳
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✷✾ ✴ ✹✶
xx ≡ λπ. [π] : C(A) → list C(A) yx ≡ λπ. [ ] : C(A) → list C(Γi) (λy. t)x ≡ λ(y, π). tx π : W(A) × C(B) → list C(Γi) (t u)x ≡ λπ. (((snd t•) π u•) ❃ ❃❂ ux) @ tx (u•, π) : C(B) → list C(Γi)
✭❲❡ ❝❛♥ ❣❡♥❡r❛❧✐③❡ t❤✐s ✐♥t❡r♣r❡t❛t✐♦♥ t♦ ❛❧❣❡❜r❛✐❝ ❞❛t❛t②♣❡s✳✮
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✸✵ ✴ ✹✶
❚❤❡ st❛♥❞❛r❞ ❉✐❛❧❡❝t✐❝❛ ♦♥❧② r❡t✉r♥s ♦♥❡ st❛❝❦
t❤❡ ✜rst ❝♦rr❡❝t st❛❝❦✱ ❞②♥❛♠✐❝❛❧❧② t❡st❡❞
❚❤✐s ✐s s♦♠❡❤♦✇ ❛ ✇❡❛❦ ❢♦r♠ ♦❢ ❞❡❧✐♠✐t❡❞ ❝♦♥tr♦❧
■♥s♣❡❝t❛❜❧❡ st❛❝❦s✿ ✈s✳ ❋✐rst ❝❧❛ss ❛❝❝❡ss t♦ t❤♦s❡ st❛❝❦s ✇✐t❤ ❖r t❤r♦✉❣❤ ❛ ❝♦♥tr♦❧ ♦♣❡r❛t♦r
❲❡ ❝❛♥ ❞♦ t❤❡ s❛♠❡ t❤✐♥❣ ✇✐t❤ ♦t❤❡r ❝❛❧❧✐♥❣ ❝♦♥✈❡♥t✐♦♥s
❚❤❡ ♣r♦t♦❤✐st♦r✐❝ ❉✐❛❧❡❝t✐❝❛ ✇❛s ❝❛❧❧✲❜②✲♥❛♠❡ ❈❤♦♦s❡ ②♦✉r ❢❛✈♦r✐t❡ tr❛♥s❧❛t✐♦♥ ✐♥t♦ ▲▲✦
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✸✶ ✴ ✹✶
❚❤❡ st❛♥❞❛r❞ ❉✐❛❧❡❝t✐❝❛ ♦♥❧② r❡t✉r♥s ♦♥❡ st❛❝❦
t❤❡ ✜rst ❝♦rr❡❝t st❛❝❦✱ ❞②♥❛♠✐❝❛❧❧② t❡st❡❞
❚❤✐s ✐s s♦♠❡❤♦✇ ❛ ✇❡❛❦ ❢♦r♠ ♦❢ ❞❡❧✐♠✐t❡❞ ❝♦♥tr♦❧
■♥s♣❡❝t❛❜❧❡ st❛❝❦s✿ ∼A ✈s✳ ¬A ❋✐rst ❝❧❛ss ❛❝❝❡ss t♦ t❤♦s❡ st❛❝❦s ✇✐t❤ (−)x ❖r t❤r♦✉❣❤ ❛ ❝♦♥tr♦❧ ♦♣❡r❛t♦r D : (A → B) → A → ∼B → list(∼A)
❲❡ ❝❛♥ ❞♦ t❤❡ s❛♠❡ t❤✐♥❣ ✇✐t❤ ♦t❤❡r ❝❛❧❧✐♥❣ ❝♦♥✈❡♥t✐♦♥s
❚❤❡ ♣r♦t♦❤✐st♦r✐❝ ❉✐❛❧❡❝t✐❝❛ ✇❛s ❝❛❧❧✲❜②✲♥❛♠❡ ❈❤♦♦s❡ ②♦✉r ❢❛✈♦r✐t❡ tr❛♥s❧❛t✐♦♥ ✐♥t♦ ▲▲✦
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✸✶ ✴ ✹✶
❚❤❡ st❛♥❞❛r❞ ❉✐❛❧❡❝t✐❝❛ ♦♥❧② r❡t✉r♥s ♦♥❡ st❛❝❦
t❤❡ ✜rst ❝♦rr❡❝t st❛❝❦✱ ❞②♥❛♠✐❝❛❧❧② t❡st❡❞
❚❤✐s ✐s s♦♠❡❤♦✇ ❛ ✇❡❛❦ ❢♦r♠ ♦❢ ❞❡❧✐♠✐t❡❞ ❝♦♥tr♦❧
■♥s♣❡❝t❛❜❧❡ st❛❝❦s✿ ∼A ✈s✳ ¬A ❋✐rst ❝❧❛ss ❛❝❝❡ss t♦ t❤♦s❡ st❛❝❦s ✇✐t❤ (−)x ❖r t❤r♦✉❣❤ ❛ ❝♦♥tr♦❧ ♦♣❡r❛t♦r D : (A → B) → A → ∼B → list(∼A)
❲❡ ❝❛♥ ❞♦ t❤❡ s❛♠❡ t❤✐♥❣ ✇✐t❤ ♦t❤❡r ❝❛❧❧✐♥❣ ❝♦♥✈❡♥t✐♦♥s
❚❤❡ ♣r♦t♦❤✐st♦r✐❝ ❉✐❛❧❡❝t✐❝❛ ✇❛s ❝❛❧❧✲❜②✲♥❛♠❡ ❈❤♦♦s❡ ②♦✉r ❢❛✈♦r✐t❡ tr❛♥s❧❛t✐♦♥ ✐♥t♦ ▲▲✦
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✸✶ ✴ ✹✶
❆❝t✉❛❧❧②✱ t❤❡r❡ ✐s s♦♠❡t❤✐♥❣ ✇r♦♥❣✳ Pr♦❞✉❝❡❞ st❛❝❦s ❛r❡ t❤❡ r✐❣❤t ♦♥❡s✳✳✳ ❚❤❡② ❤❛✈❡ t❤❡ r✐❣❤t ♠✉❧t✐♣❧✐❝✐t②✳✳✳ ❇✉t t❤❡② ❛r❡ ♥♦t r❡s♣❡❝t✐♥❣ t❤❡ ❑❆▼ ♦r❞❡r✦ ❙t✐❧❧ ♥♦t st❛❜❧❡ ❜② ❲❡ ❤❛✈❡ t♦ ✉s❡ ✜♥✐t❡ ♠✉❧t✐s❡ts ❢♦r ✐t t♦ ✇♦r❦ ❚❤❡ ❢❛✉❧t② ♦♥❡ ✐s t❤❡ ❛♣♣❧✐❝❛t✐♦♥ ❝❛s❡ ✭♠♦r❡ ❣❡♥❡r❛❧❧② ❞✉♣❧✐❝❛t✐♦♥✮✳ ❃ ❃❂
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✸✷ ✴ ✹✶
❆❝t✉❛❧❧②✱ t❤❡r❡ ✐s s♦♠❡t❤✐♥❣ ✇r♦♥❣✳ Pr♦❞✉❝❡❞ st❛❝❦s ❛r❡ t❤❡ r✐❣❤t ♦♥❡s✳✳✳ ❚❤❡② ❤❛✈❡ t❤❡ r✐❣❤t ♠✉❧t✐♣❧✐❝✐t②✳✳✳ ❇✉t t❤❡② ❛r❡ ♥♦t r❡s♣❡❝t✐♥❣ t❤❡ ❑❆▼ ♦r❞❡r✦ ❙t✐❧❧ ♥♦t st❛❜❧❡ ❜② ❲❡ ❤❛✈❡ t♦ ✉s❡ ✜♥✐t❡ ♠✉❧t✐s❡ts ❢♦r ✐t t♦ ✇♦r❦ ❚❤❡ ❢❛✉❧t② ♦♥❡ ✐s t❤❡ ❛♣♣❧✐❝❛t✐♦♥ ❝❛s❡ ✭♠♦r❡ ❣❡♥❡r❛❧❧② ❞✉♣❧✐❝❛t✐♦♥✮✳ ❃ ❃❂
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✸✷ ✴ ✹✶
❆❝t✉❛❧❧②✱ t❤❡r❡ ✐s s♦♠❡t❤✐♥❣ ✇r♦♥❣✳ Pr♦❞✉❝❡❞ st❛❝❦s ❛r❡ t❤❡ r✐❣❤t ♦♥❡s✳✳✳ ❚❤❡② ❤❛✈❡ t❤❡ r✐❣❤t ♠✉❧t✐♣❧✐❝✐t②✳✳✳ ❇✉t t❤❡② ❛r❡ ♥♦t r❡s♣❡❝t✐♥❣ t❤❡ ❑❆▼ ♦r❞❡r✦ ❙t✐❧❧ ♥♦t st❛❜❧❡ ❜② ❲❡ ❤❛✈❡ t♦ ✉s❡ ✜♥✐t❡ ♠✉❧t✐s❡ts ❢♦r ✐t t♦ ✇♦r❦ ❚❤❡ ❢❛✉❧t② ♦♥❡ ✐s t❤❡ ❛♣♣❧✐❝❛t✐♦♥ ❝❛s❡ ✭♠♦r❡ ❣❡♥❡r❛❧❧② ❞✉♣❧✐❝❛t✐♦♥✮✳ ❃ ❃❂
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✸✷ ✴ ✹✶
❆❝t✉❛❧❧②✱ t❤❡r❡ ✐s s♦♠❡t❤✐♥❣ ✇r♦♥❣✳ Pr♦❞✉❝❡❞ st❛❝❦s ❛r❡ t❤❡ r✐❣❤t ♦♥❡s✳✳✳ ❚❤❡② ❤❛✈❡ t❤❡ r✐❣❤t ♠✉❧t✐♣❧✐❝✐t②✳✳✳ ❇✉t t❤❡② ❛r❡ ♥♦t r❡s♣❡❝t✐♥❣ t❤❡ ❑❆▼ ♦r❞❡r✦ ❙t✐❧❧ ♥♦t st❛❜❧❡ ❜② β ❲❡ ❤❛✈❡ t♦ ✉s❡ ✜♥✐t❡ ♠✉❧t✐s❡ts ❢♦r ✐t t♦ ✇♦r❦ ❚❤❡ ❢❛✉❧t② ♦♥❡ ✐s t❤❡ ❛♣♣❧✐❝❛t✐♦♥ ❝❛s❡ ✭♠♦r❡ ❣❡♥❡r❛❧❧② ❞✉♣❧✐❝❛t✐♦♥✮✳ ❃ ❃❂
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✸✷ ✴ ✹✶
❆❝t✉❛❧❧②✱ t❤❡r❡ ✐s s♦♠❡t❤✐♥❣ ✇r♦♥❣✳ Pr♦❞✉❝❡❞ st❛❝❦s ❛r❡ t❤❡ r✐❣❤t ♦♥❡s✳✳✳ ❚❤❡② ❤❛✈❡ t❤❡ r✐❣❤t ♠✉❧t✐♣❧✐❝✐t②✳✳✳ ❇✉t t❤❡② ❛r❡ ♥♦t r❡s♣❡❝t✐♥❣ t❤❡ ❑❆▼ ♦r❞❡r✦ ❙t✐❧❧ ♥♦t st❛❜❧❡ ❜② β ❲❡ ❤❛✈❡ t♦ ✉s❡ ✜♥✐t❡ ♠✉❧t✐s❡ts M ❢♦r ✐t t♦ ✇♦r❦ ❚❤❡ ❢❛✉❧t② ♦♥❡ ✐s t❤❡ ❛♣♣❧✐❝❛t✐♦♥ ❝❛s❡ ✭♠♦r❡ ❣❡♥❡r❛❧❧② ❞✉♣❧✐❝❛t✐♦♥✮✳ ❃ ❃❂
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✸✷ ✴ ✹✶
❆❝t✉❛❧❧②✱ t❤❡r❡ ✐s s♦♠❡t❤✐♥❣ ✇r♦♥❣✳ Pr♦❞✉❝❡❞ st❛❝❦s ❛r❡ t❤❡ r✐❣❤t ♦♥❡s✳✳✳ ❚❤❡② ❤❛✈❡ t❤❡ r✐❣❤t ♠✉❧t✐♣❧✐❝✐t②✳✳✳ ❇✉t t❤❡② ❛r❡ ♥♦t r❡s♣❡❝t✐♥❣ t❤❡ ❑❆▼ ♦r❞❡r✦ ❙t✐❧❧ ♥♦t st❛❜❧❡ ❜② β ❲❡ ❤❛✈❡ t♦ ✉s❡ ✜♥✐t❡ ♠✉❧t✐s❡ts M ❢♦r ✐t t♦ ✇♦r❦ ❚❤❡ ❢❛✉❧t② ♦♥❡ ✐s t❤❡ ❛♣♣❧✐❝❛t✐♦♥ ❝❛s❡ ✭♠♦r❡ ❣❡♥❡r❛❧❧② ❞✉♣❧✐❝❛t✐♦♥✮✳ (t u)x ≡ λπ. (((snd t•) π u•) ❃ ❃❂ ux) @ tx (u•, π)
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✸✷ ✴ ✹✶
❚❤❡ ❑❆▼ ✐♠♣♦s❡s ✉s s❡q✉❡♥t✐❛❧✐t② ❲❡ ✇❛♥t t♦ r❡✢❡❝t ✐t ✐♥t♦ t❤❡ tr❛♥s❧❛t✐♦♥ ❆❧❛s✱ ♥♦ ✇❛② t♦ ❞♦ t❤❛t ❚❤❡ tr❛♥s❧❛t✐♦♥ ✐s ❢❛r t♦♦ s②♠♠❡tr✐❝❛❧
❲❡ ✇❛♥t ✐♥t❡r❧❡❛✈✐♥❣ ❉✐❛❧❡❝t✐❝❛ ❝❛♥✬t ❛❝❤✐❡✈❡ ✐t ❛s ✐s P♦❧❛r✐③❛t✐♦♥❄ ❚❡♥s♦r✐❛❧ ❧♦❣✐❝❄ ❉✉♠♣ ❉✐❛❧❡❝t✐❝❛❄
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✸✸ ✴ ✹✶
❚❤❡ ❑❆▼ ✐♠♣♦s❡s ✉s s❡q✉❡♥t✐❛❧✐t② ❲❡ ✇❛♥t t♦ r❡✢❡❝t ✐t ✐♥t♦ t❤❡ tr❛♥s❧❛t✐♦♥ ❆❧❛s✱ ♥♦ ✇❛② t♦ ❞♦ t❤❛t ❚❤❡ ` tr❛♥s❧❛t✐♦♥ ✐s ❢❛r t♦♦ s②♠♠❡tr✐❝❛❧
❲❡ ✇❛♥t ✐♥t❡r❧❡❛✈✐♥❣ ❉✐❛❧❡❝t✐❝❛ ❝❛♥✬t ❛❝❤✐❡✈❡ ✐t ❛s ✐s P♦❧❛r✐③❛t✐♦♥❄ ❚❡♥s♦r✐❛❧ ❧♦❣✐❝❄ ❉✉♠♣ ❉✐❛❧❡❝t✐❝❛❄
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✸✸ ✴ ✹✶
❲❡ st✐❧❧ ❞✐❞ ♥♦t r❡❛❝❤ t❤❡ ♣r♦t♦❤✐st♦r✐❝ ❉✐❛❧❡❝t✐❝❛✳ ❚♦ ❡♥❝♦❞❡ ▼P ❛♥❞ ■P ✇❡ ♥❡❡❞ ∅ ❛s ❛ ♣r♦♦❢✳
♥♦t ♦♥❧② ❛s ❛ st❛❝❦ ∅ ❜❡❤❛✈❡s ❧✐❦❡ ❛♥ ❡①❝❡♣t✐♦♥
■♥ ♦✉r s❡tt✐♥❣ ✇❡ ♦♥❧② ❣❡t ❛ ✇❡❛❦ ✈❡rs✐♦♥ ♦❢ ▼P ❆♥❞ ♥♦t ■P✳
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✸✹ ✴ ✹✶
❲❡ st✐❧❧ ❞✐❞ ♥♦t r❡❛❝❤ t❤❡ ♣r♦t♦❤✐st♦r✐❝ ❉✐❛❧❡❝t✐❝❛✳ ❚♦ ❡♥❝♦❞❡ ▼P ❛♥❞ ■P ✇❡ ♥❡❡❞ ∅ ❛s ❛ ♣r♦♦❢✳
♥♦t ♦♥❧② ❛s ❛ st❛❝❦ ∅ ❜❡❤❛✈❡s ❧✐❦❡ ❛♥ ❡①❝❡♣t✐♦♥
■♥ ♦✉r s❡tt✐♥❣ ✇❡ ♦♥❧② ❣❡t ❛ ✇❡❛❦ ✈❡rs✐♦♥ ♦❢ ▼P
❆♥❞ ♥♦t ■P✳
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✸✹ ✴ ✹✶
❲❤❛t ❛❜♦✉t ♠♦r❡ ❡①♣r❡ss✐✈❡ s②st❡♠s❄ ❲❡ ❢♦❧❧♦✇ t❤❡ ❝♦♠♣✉t❛t✐♦♥ ✐♥t✉✐t✐♦♥ ✇❡ ♣r❡s❡♥t❡❞ ✳✳✳ ❛♥❞ ✇❡ ❛♣♣❧② ❉✐❛❧❡❝t✐❝❛ t♦ ❞❡♣❡♥❞❡♥t t②♣❡s
s✉❜s✉♠✐♥❣ ✜rst✲♦r❞❡r ❧♦❣✐❝❀ ❛ ♣r♦♦❢✲r❡❧❡✈❛♥t ∀❀ t♦✇❛r❞s CCω ❛♥❞ ❢✉rt❤❡r✦
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✸✺ ✴ ✹✶
❲❡ ❦❡❡♣ t❤❡ ❈❇◆ λ✲❝❛❧❝✉❧✉s
✐t ❝❛♥ ❜❡ ❧✐❢t❡❞ r❡❛❞✐❧② t♦ ❞❡♣❡♥❞❡♥t t②♣❡s A → B ❜❡❝♦♠❡s Πx : A. B A × B ❜❡❝♦♠❡s Σx : A. B ♥♦t❤✐♥❣ s♣❡❝✐❛❧ t♦ ❞♦✦
❉❡s✐❣♥ ❝❤♦✐❝❡✿ t②♣❡s ❤❛✈❡ ♥♦ ❝♦♠♣✉t❛t✐♦♥❛❧ ❝♦♥t❡♥t ✭❡✛❡❝t✲❢r❡❡✮✿
❛ ❜✐t ❞✐s❛♣♣♦✐♥t✐♥❣❀ ❜✉t ✐t ✇♦r❦s✳✳✳ ❛♥❞ t❤❡ ✉s✉❛❧ ❈❈ ♣r❡s❡♥t❛t✐♦♥ ❞♦❡s ♥♦t ❤❡❧♣ ♠✉❝❤✦
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✸✻ ✴ ✹✶
❲❡ ❦❡❡♣ t❤❡ ❈❇◆ λ✲❝❛❧❝✉❧✉s
✐t ❝❛♥ ❜❡ ❧✐❢t❡❞ r❡❛❞✐❧② t♦ ❞❡♣❡♥❞❡♥t t②♣❡s A → B ❜❡❝♦♠❡s Πx : A. B A × B ❜❡❝♦♠❡s Σx : A. B ♥♦t❤✐♥❣ s♣❡❝✐❛❧ t♦ ❞♦✦
❉❡s✐❣♥ ❝❤♦✐❝❡✿ t②♣❡s ❤❛✈❡ ♥♦ ❝♦♠♣✉t❛t✐♦♥❛❧ ❝♦♥t❡♥t ✭❡✛❡❝t✲❢r❡❡✮✿
❛ ❜✐t ❞✐s❛♣♣♦✐♥t✐♥❣❀ ❜✉t ✐t ✇♦r❦s✳✳✳ ❛♥❞ t❤❡ ✉s✉❛❧ ❈❈ ♣r❡s❡♥t❛t✐♦♥ ❞♦❡s ♥♦t ❤❡❧♣ ♠✉❝❤✦
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✸✻ ✴ ✹✶
■❞❡❛✿ ✐❢ A ✐s ❛ t②♣❡✱ A• ≡ (W(A), C(A)) : Type × Type Ax ≡ λπ. [] ✭❡✛❡❝t✲❢r❡❡✮ ❲❡ ❣❡t✿
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✸✼ ✴ ✹✶
■❞❡❛✿ ✐❢ A ✐s ❛ t②♣❡✱ A• ≡ (W(A), C(A)) : Type × Type Ax ≡ λπ. [] ✭❡✛❡❝t✲❢r❡❡✮ ❲❡ ❣❡t✿
Type• ≡ (Type × Type, 1) Typex ≡ λπ. [ ] (Πy : A. B)• ≡ (Πy : W(A). W(B)) × (Πy : W(A). C(B) → M C(A)) , Σy : W(A). C(B) (Πy : A. B)x ≡ λπ. [ ]
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✸✼ ✴ ✹✶
❚❤❡ tr❛♥s❧❛t✐♦♥ ✐s s♦✉♥❞✱ ❜✉t ✐t✬s ♥♦t r❡❛❧❧② ♣✉r❡ ❈■❈✳ ❲❡ ♥❡❡❞ ✜♥✐t❡ ♠✉❧t✐s❡ts
❍■❚s✱ ❍■❚s✱ ❍■❚s✦
❲❡ ♥❡❡❞ s♦♠❡ ❝♦♠♠✉t❛t✐✈❡ ❝✉t r✉❧❡s
❋✐rst ❝❧❛ss ✭r❡❛❞✿ ♥❡❣❛t✐✈❡✮ r❡❝♦r❞s ♠❛② ❞♦ t❤❡ tr✐❝❦
❖r ❡①t❡♥s✐♦♥❛❧✐t② ❤❛♠♠❡r
▼❛②❜❡ ❖✉r②✲❧✐❦❡ tr✐❝❦s
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✸✽ ✴ ✹✶
❚❤❡ tr❛♥s❧❛t✐♦♥ ✐s s♦✉♥❞✱ ❜✉t ✐t✬s ♥♦t r❡❛❧❧② ♣✉r❡ ❈■❈✳ ❲❡ ♥❡❡❞ ✜♥✐t❡ ♠✉❧t✐s❡ts
❍■❚s✱ ❍■❚s✱ ❍■❚s✦
❲❡ ♥❡❡❞ s♦♠❡ ❝♦♠♠✉t❛t✐✈❡ ❝✉t r✉❧❡s
❋✐rst ❝❧❛ss ✭r❡❛❞✿ ♥❡❣❛t✐✈❡✮ r❡❝♦r❞s ♠❛② ❞♦ t❤❡ tr✐❝❦
❖r ❡①t❡♥s✐♦♥❛❧✐t② ❤❛♠♠❡r
▼❛②❜❡ ❖✉r②✲❧✐❦❡ tr✐❝❦s
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✸✽ ✴ ✹✶
❲❡ ❝❛♥ ♦❜t❛✐♥ ❞❡♣❡♥❞❡♥t ❞❡str✉❝t✐♦♥ q✉✐t❡ ❡❛s✐❧②
Γ ⊢ t : A + B Γ, x : A ⊢ u1 : C[L x] Γ, y : B ⊢ u2 : C[R y] Γ ⊢ case t with [L x ⇒ u1 | R y ⇒ u2] : C[t]
❏✉st t✇❡❛❦ t❤❡ ❧✐♥❡❛r ❞❡❝♦♠♣♦s✐t✐♦♥ ❛♥❞ t❤❡r❡ ②♦✉ ❣♦✦
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✸✾ ✴ ✹✶
❆❝t✉❛❧❧②✱ ❉✐❛❧❡❝t✐❝❛ ✐s q✉✐t❡ s✐♠♣❧❡✳
✳✳✳ ❛t ❧❡❛st ♦♥❝❡ ✇❡ r❡♠♦✈❡❞ ❡♥❝♦❞✐♥❣ ❛rt✐❢❛❝ts
■t ✐s ❛♥ ❛♣♣r♦①✐♠❛t✐♦♥ ♦❢ t✇♦ s✐❞❡✲❡✛❡❝ts✿
❆ ❜✐t ♦❢ ❞❡❧✐♠✐t❡❞ ❝♦♥tr♦❧ ✭t❤❡ ♣❛rt✮ ❆ ❢♦r♠ ♦❢ ❡①❝❡♣t✐♦♥s ✭✇✐t❤ ✮
❇✉t ✐s ✐s ♣❛rt✐❛❧❧② ✇r♦♥❣✿
✐t ✐s ♦❜❧✐✈✐♦✉s ♦❢ s❡q✉❡♥t✐❛❧✐t② ❤♦✇ ❝❛♥ ✇❡ ✜① ✐t❄
❚❤❡ ❞❡❧✐♠✐t❡❞ ❝♦♥tr♦❧ ♣❛rt ❝❛♥ ❜❡ ❧✐❢t❡❞ s❡❛♠❧❡ss❧② t♦
❛s s♦♦♥ ❛s ✇❡ ❤❛✈❡ ❛ ❧✐tt❧❡ ❜✐t ♠♦r❡ t❤❛♥ ❈❈ ✇❡ ♥❡❡❞ ❛ ♠♦r❡ ❝♦♠♣✉t❛t✐♦♥✲r❡❧❡✈❛♥t ♣r❡s❡♥t❛t✐♦♥ ♦❢ ❈❈
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✹✵ ✴ ✹✶
❆❝t✉❛❧❧②✱ ❉✐❛❧❡❝t✐❝❛ ✐s q✉✐t❡ s✐♠♣❧❡✳
✳✳✳ ❛t ❧❡❛st ♦♥❝❡ ✇❡ r❡♠♦✈❡❞ ❡♥❝♦❞✐♥❣ ❛rt✐❢❛❝ts
■t ✐s ❛♥ ❛♣♣r♦①✐♠❛t✐♦♥ ♦❢ t✇♦ s✐❞❡✲❡✛❡❝ts✿
❆ ❜✐t ♦❢ ❞❡❧✐♠✐t❡❞ ❝♦♥tr♦❧ ✭t❤❡ (−)x ♣❛rt✮ ❆ ❢♦r♠ ♦❢ ❡①❝❡♣t✐♦♥s ✭✇✐t❤ ∅✮
❇✉t ✐s ✐s ♣❛rt✐❛❧❧② ✇r♦♥❣✿
✐t ✐s ♦❜❧✐✈✐♦✉s ♦❢ s❡q✉❡♥t✐❛❧✐t② ❤♦✇ ❝❛♥ ✇❡ ✜① ✐t❄
❚❤❡ ❞❡❧✐♠✐t❡❞ ❝♦♥tr♦❧ ♣❛rt ❝❛♥ ❜❡ ❧✐❢t❡❞ s❡❛♠❧❡ss❧② t♦
❛s s♦♦♥ ❛s ✇❡ ❤❛✈❡ ❛ ❧✐tt❧❡ ❜✐t ♠♦r❡ t❤❛♥ ❈❈ ✇❡ ♥❡❡❞ ❛ ♠♦r❡ ❝♦♠♣✉t❛t✐♦♥✲r❡❧❡✈❛♥t ♣r❡s❡♥t❛t✐♦♥ ♦❢ ❈❈
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✹✵ ✴ ✹✶
❆❝t✉❛❧❧②✱ ❉✐❛❧❡❝t✐❝❛ ✐s q✉✐t❡ s✐♠♣❧❡✳
✳✳✳ ❛t ❧❡❛st ♦♥❝❡ ✇❡ r❡♠♦✈❡❞ ❡♥❝♦❞✐♥❣ ❛rt✐❢❛❝ts
■t ✐s ❛♥ ❛♣♣r♦①✐♠❛t✐♦♥ ♦❢ t✇♦ s✐❞❡✲❡✛❡❝ts✿
❆ ❜✐t ♦❢ ❞❡❧✐♠✐t❡❞ ❝♦♥tr♦❧ ✭t❤❡ (−)x ♣❛rt✮ ❆ ❢♦r♠ ♦❢ ❡①❝❡♣t✐♦♥s ✭✇✐t❤ ∅✮
❇✉t ✐s ✐s ♣❛rt✐❛❧❧② ✇r♦♥❣✿
✐t ✐s ♦❜❧✐✈✐♦✉s ♦❢ s❡q✉❡♥t✐❛❧✐t② ❤♦✇ ❝❛♥ ✇❡ ✜① ✐t❄
❚❤❡ ❞❡❧✐♠✐t❡❞ ❝♦♥tr♦❧ ♣❛rt ❝❛♥ ❜❡ ❧✐❢t❡❞ s❡❛♠❧❡ss❧② t♦
❛s s♦♦♥ ❛s ✇❡ ❤❛✈❡ ❛ ❧✐tt❧❡ ❜✐t ♠♦r❡ t❤❛♥ ❈❈ ✇❡ ♥❡❡❞ ❛ ♠♦r❡ ❝♦♠♣✉t❛t✐♦♥✲r❡❧❡✈❛♥t ♣r❡s❡♥t❛t✐♦♥ ♦❢ ❈❈
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✹✵ ✴ ✹✶
❆❝t✉❛❧❧②✱ ❉✐❛❧❡❝t✐❝❛ ✐s q✉✐t❡ s✐♠♣❧❡✳
✳✳✳ ❛t ❧❡❛st ♦♥❝❡ ✇❡ r❡♠♦✈❡❞ ❡♥❝♦❞✐♥❣ ❛rt✐❢❛❝ts
■t ✐s ❛♥ ❛♣♣r♦①✐♠❛t✐♦♥ ♦❢ t✇♦ s✐❞❡✲❡✛❡❝ts✿
❆ ❜✐t ♦❢ ❞❡❧✐♠✐t❡❞ ❝♦♥tr♦❧ ✭t❤❡ (−)x ♣❛rt✮ ❆ ❢♦r♠ ♦❢ ❡①❝❡♣t✐♦♥s ✭✇✐t❤ ∅✮
❇✉t ✐s ✐s ♣❛rt✐❛❧❧② ✇r♦♥❣✿
✐t ✐s ♦❜❧✐✈✐♦✉s ♦❢ s❡q✉❡♥t✐❛❧✐t② ❤♦✇ ❝❛♥ ✇❡ ✜① ✐t❄
❚❤❡ ❞❡❧✐♠✐t❡❞ ❝♦♥tr♦❧ ♣❛rt ❝❛♥ ❜❡ ❧✐❢t❡❞ s❡❛♠❧❡ss❧② t♦ CCω
❛s s♦♦♥ ❛s ✇❡ ❤❛✈❡ ❛ ❧✐tt❧❡ ❜✐t ♠♦r❡ t❤❛♥ ❈❈ ✇❡ ♥❡❡❞ ❛ ♠♦r❡ ❝♦♠♣✉t❛t✐♦♥✲r❡❧❡✈❛♥t ♣r❡s❡♥t❛t✐♦♥ ♦❢ ❈❈
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✹✵ ✴ ✹✶
P✐❡rr❡✲▼❛r✐❡ Pé❞r♦t ✭PP❙✴πr2✮ ❈❛♥ ❉✐❛❧❡❝t✐❝❛ ❜r❡❛❦ ❜r✐❝❦s❄ ✷✶✴✵✸✴✷✵✶✹ ✹✶ ✴ ✹✶