{
    /(b_eq)
        (bA)(bB)
            /(zqA)(lbA)(hb!A)
                /(zqB)(lbB)(hb!B)
                    /
                        /
                            /[hb!B]/[hb!A][b_eq]
                        /
                            /[lbB]/[lbA][xnor]
                        [and]
                    /
                        [zqB]
                    [zqA]
                [bB]
            [bA]
    [YC]
|
    b_eq
}