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1 module cbc-agda where
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2
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3 open import Data.Nat
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4 open import Level renaming ( suc to succ ; zero to Zero )
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5
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6 record Env : Set where
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7 field
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8 varx : ℕ
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9 vary : ℕ
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10 open Env
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11
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12 plus-c : {l : Level} {t : Set l} → Env → (exit : Env → t) → t
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13 plus-c env exit = plus-p (vary env) env exit where
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14 plus-p : {l : Level} {t : Set l} → ℕ → Env → (exit : Env → t) → t
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15 plus-p zero env exit = exit env
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16 plus-p (suc reducer) env exit = plus-p reducer record env{varx = (suc (varx env)) ; vary = reducer} exit
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17
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18 {-# TERMINATING #-}
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19 plus-c-term : {l : Level} {t : Set l} → Env → (exit : Env → t) → t
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20 plus-c-term env exit with vary env
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21 ... | zero = exit (record { varx = varx env ; vary = vary env })
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22 ... | suc y = plus-c-term (record { varx = suc (varx env) ; vary = y }) exit
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23
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24 plus : ℕ → ℕ → Env
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25 plus x y = plus-c (record { varx = x ; vary = y }) (λ env → env)
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