inPatrol(barracuda,mark).
inPatrol(barracuda,ben).
inPatrol(barracuda,reed).

inPatrol(dragon,kevin).
inPatrol(dragon,chris).
inPatrol(dragon,zach).

patrolLeader(ben).
patrolLeader(kevin).

samePatrol(Scout1,Scout2) :- inPatrol(Patrol,Scout1), inPatrol(Patrol,Scout2), Scout1 \= Scout2.
leads(Leader,Scout) :- patrolLeader(Leader), samePatrol(Leader,Scout).