{        (g) /?     /?           /?     /?           /[1][g] | dequeEmpty  }
{ (item) (g) /[item]/[dequeEmpty]/[item]/[dequeEmpty]/[0][g] | dequeSingle }

{
    (isEmpty)(lPopped)(lItem)(rPopped)(rItem)
        [lPopped]
|
    dequeLPopped
}

{
    (isEmpty)(lPopped)(lItem)(rPopped)(rItem)
        [lItem]
|
    dequeLItem
}

{
    (isEmpty)(lPopped)(lItem)(rPopped)(rItem)
        [rPopped]
|
    dequeRPopped
}

{
    (isEmpty)(lPopped)(lItem)(rPopped)(rItem)
        [rItem]
|
    dequeRItem
}

{
    /(dequeLPush)
        (deque)(item)
            /(isEmpty)(lPopped)(lItem)(rPopped)(rItem)
                /
                    (g) /[rItem]/</[item]/[rPopped][dequeLPush]>/[item]/[deque]/[0] [g]
                /
                    /[item][dequeSingle]
                [isEmpty]
            [deque]
    [YC]
|
    dequeLPush
}

{
    /(dequeRPush)
        (deque)(item)
            /(isEmpty)(lPopped)(lItem)(rPopped)(rItem)
                /
                    (g) /[item]/[deque]/[lItem]/</[item]/[lPopped][dequeRPush]>/[0] [g]
                /
                    /[item][dequeSingle]
                [isEmpty]
            [deque]
    [YC]
|
    dequeRPush
}

{
    (_0)(_1)(_add)
        /(dequeLength)
            (isEmpty)(lPopped)(lItem)(rPopped)(rItem)
                /
                    /
                        /[dequeLength][lPopped]
                    /
                        [_1]
                    [_add]
                /
                    [_0]
                [isEmpty]
        [YC]
|
    dequeLLength
}

{
    (_0)(_1)(_add)
        /(dequeLength)
            (isEmpty)(lPopped)(lItem)(rPopped)(rItem)
                /
                    /
                        /[dequeLength][rPopped]
                    /
                        [_1]
                    [_add]
                /
                    [_0]
                [isEmpty]
        [YC]
|
    dequeRLength
}