Step four in creating a fold over a BinomialHeap

BinomialHeap fold step 4.fs

static member private foldHeapStep4 nodeF leafV (h : list<BinomialTree<'a>>) = 

    let rec loop (h : list<BinomialTree<'a>>) cont =
        match h with
        | Node(_, a, [])::[] -> loop []  (fun lacc ->  
                                loop [] (fun racc -> 
                                cont (nodeF a lacc racc)))
        | Node(_, a, h')::[] -> loop h'  (fun lacc ->  
                                loop [] (fun racc -> 
                                cont (nodeF a lacc racc))) 
        | Node(_, a, [])::tl -> loop []  (fun lacc ->  
                                loop tl (fun racc ->
                                cont (nodeF a lacc racc))) 
        | Node(_, a, h')::tl -> loop h'  (fun lacc ->  
                                loop tl (fun racc -> 
                                cont (nodeF a lacc racc))) 
        | _ -> cont leafV
           
    loop h (fun x -> x)

static member private inOrderStep4 (h : list<BinomialTree<'a>>) = 
    let x = (BinomialHeap.foldHeap (fun x l r acc -> l (x :: (r acc))) (fun acc -> acc) h)
    x []