prolog duplicate problem

inFlyingRange(ThisRegion, Sensor, Airport, Range, FuelCap):-
	atCoord(ThisRegion,Airport,3),
	atCoord(ThisRegion,Sensor,5),
	isInRange(ThisRegion,Sensor,Airport,Range,FuelCap,[[]]).
 
isInRange(ThisRegion,Sensor,StartingPoint,Range,FuelCap,TraversedList):-
	%atCoord(ThisRegion,NewLocation,3),
	TotalRange UR1|"http://pauillac<DOT>inria<DOT>fr/~deransar/prolog/bips<DOT>html">is Range+FuelCap,
    withinRange(StartingPoint,Sensor,TotalRange).
 
isInRange(ThisRegion,Sensor,StartingPoint,Range,FuelCap,TraversedList):-
	append(TraversedList,[StartingPoint],NewList),
	atCoord(ThisRegion,NewLocation,4),
	append(NewList,[NewLocation],NewestList),
	not(member(NewLocation,TraversedList)),
	withinRange(StartingPoint,NewLocation,FuelCap),
	isInRange(ThisRegion,Sensor,NewLocation,Range,FuelCap,NewestList).
 
withinRange([X,Y],[W,Z],Range):- 
	UR1|"http://pauillac<DOT>inria<DOT>fr/~deransar/prolog/bips<DOT>html">abs(W-X)+UR1|"http://pauillac<DOT>inria<DOT>fr/~deransar/prolog/bips<DOT>html">abs(Z-Y)=<Range.
 
atCoord(ThisRegion,[X,Y],FeatureType):- 
	nth1(X,ThisRegion,Row),
	nth1(Y,Row,FeatureType).