*SUPPORT*
IN: fep kiki OUT: RED RED
IN: fep fep OUT: RED RED
IN: fep lug gazzer wif OUT: RED GREEN BLUE
IN: fep gazzer lug OUT: BLUE RED
IN: fep gazzer dax OUT: YELLOW RED
IN: wif fep kiki OUT: GREEN RED RED
IN: dax tufa dax OUT: YELLOW YELLOW
IN: dax tufa fep OUT: RED YELLOW
IN: lug gazzer dax OUT: YELLOW BLUE
IN: fep gazzer fep OUT: RED RED
IN: dax gazzer lug OUT: BLUE YELLOW
IN: fep OUT: RED
IN: fep tufa fep OUT: RED RED
IN: dax dax gazzer dax OUT: YELLOW YELLOW YELLOW

*QUERY*
IN: dax fep dax lug dax wif OUT: YELLOW RED YELLOW BLUE YELLOW GREEN
IN: dax OUT: YELLOW
IN: lug OUT: BLUE
IN: wif OUT: GREEN
IN: lug lug OUT: BLUE BLUE
IN: lug tufa wif OUT: GREEN BLUE
IN: wif gazzer fep OUT: RED GREEN
IN: dax kiki OUT: YELLOW YELLOW
IN: dax gazzer dax OUT: YELLOW YELLOW
IN: wif tufa fep OUT: RED GREEN

*GRAMMAR*
fep -> RED 
 wif -> GREEN 
 lug -> BLUE 
 dax -> YELLOW 
 u1 tufa u2 -> [u2] [u1] 
 u1 kiki -> [u1] [u1] 
 u1 gazzer u2 -> [u2] [u1] 
 u1 x1 -> [u1] [x1] 
 