*SUPPORT*
IN: wif zup gazzer dax fep tufa kiki gazzer OUT: GREEN RED PURPLE BLUE GREEN
IN: gazzer zup dax gazzer kiki dax OUT: RED GREEN GREEN RED
IN: gazzer fep tufa zup wif fep gazzer OUT: BLUE GREEN GREEN PURPLE
IN: tufa OUT: PURPLE
IN: dax dax OUT: RED RED
IN: dax OUT: RED
IN: tufa gazzer OUT: PURPLE GREEN
IN: gazzer fep dax OUT: GREEN RED
IN: gazzer fep tufa OUT: GREEN PURPLE
IN: tufa fep dax OUT: PURPLE RED
IN: wif fep wif OUT: BLUE BLUE
IN: dax kiki gazzer OUT: RED GREEN
IN: wif kiki tufa OUT: BLUE PURPLE
IN: tufa fep tufa OUT: PURPLE PURPLE

*QUERY*
IN: wif OUT: BLUE
IN: dax fep wif OUT: RED BLUE
IN: wif dax kiki tufa OUT: BLUE RED PURPLE
IN: tufa fep wif OUT: PURPLE BLUE
IN: gazzer fep gazzer OUT: GREEN GREEN
IN: tufa tufa tufa fep tufa OUT: PURPLE PURPLE PURPLE PURPLE
IN: dax wif dax OUT: RED BLUE RED
IN: gazzer OUT: GREEN
IN: gazzer wif fep gazzer OUT: GREEN BLUE GREEN
IN: wif fep dax zup tufa wif OUT: PURPLE BLUE BLUE RED

*GRAMMAR*
wif -> BLUE 
 gazzer -> GREEN 
 dax -> RED 
 tufa -> PURPLE 
 x1 kiki u1 -> [x1] [u1] 
 u1 fep u2 -> [u1] [u2] 
 x1 zup x2 -> [x2] [x1] 
 u1 x1 -> [u1] [x1] 
 