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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def combining_setup(self):
 """ Setup for some special F2L cases. """

        (slot_type, (corner_slot, edge_slot), (corner, edge)) = self.get_slot()
        cycle = ["FR", "RB", "BL", "LF"]
        if slot_type == "SLOTFREE":
            return ("FR", Formula(Step("y") * cycle.index(self.pair) or []))
        elif slot_type == "CSLOTFREE":
            return (cycle[-(cycle.index(edge_slot) - cycle.index(self.pair))], 
                    Formula(Step("y") * cycle.index(edge_slot) or [])) 
        elif slot_type in ("ESLOTFREE", "WRONGSLOT"):
            return (cycle[-(cycle.index(corner_slot) - cycle.index(self.pair))], 
                    Formula(Step("y") * cycle.index(corner_slot) or [])) 
        elif slot_type == "DIFFSLOT":
            if corner_slot != self.pair: corner_slot, edge_slot = edge_slot, corner_slot
            result = Formula(Step("y") * cycle.index(edge_slot) or [])
            result += Formula("R U R'")
            result += Formula(Step("y'") * cycle.index(edge_slot) or [])
            result += Formula(Step("y") * cycle.index(corner_slot) or [])
            if result[-1].face == "y" and result[-2].face == "y":
                result[-2] += result[-1]
                del result[-1]
            return (cycle[-(cycle.index(corner_slot) - cycle.index(self.pair))], result)
        else:
            return (cycle[-cycle.index(self.pair)], Formula())