reserve D for non empty set;
reserve f1,f2 for FinSequence of D;
reserve i,n,n1,n2,n3,n4,n5,n6 for Element of NAT;
reserve S for Gene-Set;
reserve p1,p2 for Individual of S;

theorem Th26:
  crossover(p1,p2,n1,n2,n3) = crossover(p1,p2,n3,n1,n2)
proof
  crossover(p1,p2,n1,n2,n3) = crossover(p1,p2,n1,n3,n2) by Th25;
  hence thesis by Th25;
end;
