caseSList.golden

--- opening "caseSList.ma" ---
--- scope checking ---
--- type checking ---
type  Nat : Set
term  Nat.zero : < Nat.zero : Nat >
term  Nat.suc : ^(y0 : Nat) -> < Nat.suc y0 : Nat >
type  Bool : Set
term  Bool.true : < Bool.true : Bool >
term  Bool.false : < Bool.false : Bool >
term  leq : Nat -> Nat -> Bool
{ leq Nat.zero n = Bool.true
; leq (Nat.suc m) Nat.zero = Bool.false
; leq (Nat.suc m) (Nat.suc n) = leq m n
}
type  Id : ^(A : Set) -> ^(a : A) -> ^ A -> Set
term  Id.refl : .[A : Set] -> .[a : A] -> < Id.refl : Id A a a >
type  True : ^ Bool -> Set
{ True b = Id Bool b Bool.true
}
term  triv : True Bool.true
term  triv = Id.refl
type  False : Bool -> Set
{ False b = Id Bool b Bool.false
}
term  triv' : False Bool.false
term  triv' = Id.refl
term  leFalse : (n : Nat) -> (m : Nat) -> False (leq n m) -> True (leq m n)
{ leFalse n Nat.zero p = triv
; leFalse (Nat.suc n) (Nat.suc m) p = leFalse n m p
; leFalse Nat.zero (Nat.suc m) ()
}
type  SList : ^ Nat -> Set
term  SList.snil : < SList.snil : SList Nat.zero >
term  SList.scons : .[shead : Nat] -> ^(stailindex : Nat) -> .[y2 : True (leq stailindex shead)] -> ^(stail : SList stailindex) -> < SList.scons shead stailindex y2 stail : SList shead >
term  maxN : Nat -> Nat -> Nat
{ maxN n m = case leq n m : Bool
             { Bool.true -> m
             ; Bool.false -> n
             }
}
term  maxLemma : (n : Nat) -> (m : Nat) -> (k : Nat) -> True (leq n k) -> True (leq m k) -> True (leq (maxN n m) k)
{ maxLemma n m k p q = case leq n m : Bool
                       { Bool.true -> q
                       ; Bool.false -> p
                       }
}
term  insert : (m : Nat) -> (n : Nat) -> SList n -> SList (maxN n m)
{ insert m .Nat.zero SList.snil = SList.scons [m] Nat.zero [triv] SList.snil
; insert m n (SList.scons [.n] k [p] l) = case leq n m : Bool
                                          { Bool.true -> SList.scons [m] n [triv] (SList.scons [n] k [p] l)
                                          ; Bool.false -> SList.scons [n] (maxN k m) [maxLemma k m n p (leFalse n m triv')] (insert m k l)
                                          }
}
--- evaluating ---
--- closing "caseSList.ma" ---