cofunIntoBoolTimesStream.err

MiniAgda by Andreas Abel and Karl Mehltretter
--- opening "cofunIntoBoolTimesStream.ma" ---
--- scope checking ---
--- type checking ---
type  Bool : Set
term  Bool.true : < Bool.true : Bool >
term  Bool.false : < Bool.false : Bool >
type  Prod : ++(A : Set) -> ++(B : Set) -> Set
term  Prod.pair : .[A : Set] -> .[B : Set] -> ^(fst : A) -> ^(snd : B) -> < Prod.pair fst snd : Prod A B >
term  fst : .[A : Set] -> .[B : Set] -> (pair : Prod A B) -> A
{ fst [A] [B] (Prod.pair #fst #snd) = #fst
}
term  snd : .[A : Set] -> .[B : Set] -> (pair : Prod A B) -> B
{ snd [A] [B] (Prod.pair #fst #snd) = #snd
}
type  BStr : - Size -> Set
term  BStr.cons : .[i : Size] -> ^(head : Bool) -> ^(tail : BStr i) -> < BStr.cons i head tail : BStr $i >
term  head : .[i : Size] -> (cons : BStr $i) -> Bool
{ head [i] (BStr.cons [.i] #head #tail) = #head
}
term  tail : .[i : Size] -> (cons : BStr $i) -> BStr i
{ tail [i] (BStr.cons [.i] #head #tail) = #tail
}
term  idAndLast : .[i : Size] -> BStr i -> Prod Bool (BStr i)
error during typechecking:
idAndLast
/// clause 1
/// pattern $i
/// checkPattern $i : matching on size, checking that target .[i : Size] -> BStr i -> Prod Bool (BStr i) ends in correct coinductive sized type
/// new i <= #
/// endsInSizedCo: BStr i -> Prod Bool (BStr i)
/// new  : (BStr v0)
/// endsInSizedCo: Prod Bool (BStr i)
/// allTypesOfTuple: detected tuple target, checking components
/// allComponentTypes: checking fields of tuple type [field fst : A,field snd : B] in environment Environ {envMap = [(B,(BStr v0)),(A,Bool)], envBound = Nothing}
/// endsInSizedCo: Bool
/// endsInSizedCo: target Bool of corecursive function is neither a CoSet or codata of size i nor a tuple type