{
    (map)
        /(dequeMap)
            (isEmpty)(lPopped)(lItem)(rPopped-unused)(rItem-unused)
                /
                    { /[dequeMap][lPopped] | lPMapped }
                    /(isEmptyL)(lPoppedL-unused)(lItemL-unused)(rPoppedL)(rItemL)
                        { /[lItem][map]        | item     }
                        /
                            (g) /[rItemL]/</[item]/[rPoppedL][dequeLPush]>/[item]/[lPMapped]/[0] [g]
                        /
                            /[item][dequeSingle]
                        [isEmptyL]
                    [lPMapped]
                /
                    [dequeEmpty]
                [isEmpty]
        [YC]
|
    dequeLMap
}

{
    (map)
        /(dequeMap)
            (isEmpty)(lPopped-unused)(lItem-unused)(rPopped)(rItem)
                /
                    { /[dequeMap][rPopped] | rPMapped }
                    /(isEmptyR)(lPoppedR)(lItemR)(rPoppedR-unused)(rItemL-unused)
                        { /[rItem][map]        | item     }
                        /
                            (g) /[item]/[rPMapped]/[lItemR]/</[item]/[lPoppedR][dequeRPush]>/[0] [g]
                        /
                            /[item][dequeSingle]
                        [isEmptyR]
                    [rPMapped]
                /
                    [dequeEmpty]
                [isEmpty]
        [YC]
|
    dequeRMap
}