let n1, n2, n3, n4 be Element of NAT ; for S being Gene-Set
for p1, p2 being Individual of S holds
( crossover (p1,p2,n1,0,0,0) = crossover (p2,p1,n1) & crossover (p1,p2,0,n2,0,0) = crossover (p2,p1,n2) & crossover (p1,p2,0,0,n3,0) = crossover (p2,p1,n3) & crossover (p1,p2,0,0,0,n4) = crossover (p2,p1,n4) )
let S be Gene-Set; for p1, p2 being Individual of S holds
( crossover (p1,p2,n1,0,0,0) = crossover (p2,p1,n1) & crossover (p1,p2,0,n2,0,0) = crossover (p2,p1,n2) & crossover (p1,p2,0,0,n3,0) = crossover (p2,p1,n3) & crossover (p1,p2,0,0,0,n4) = crossover (p2,p1,n4) )
let p1, p2 be Individual of S; ( crossover (p1,p2,n1,0,0,0) = crossover (p2,p1,n1) & crossover (p1,p2,0,n2,0,0) = crossover (p2,p1,n2) & crossover (p1,p2,0,0,n3,0) = crossover (p2,p1,n3) & crossover (p1,p2,0,0,0,n4) = crossover (p2,p1,n4) )
crossover (p1,p2,n1,0,0,0) = crossover (p1,p2,n1,0)
by Th30;
hence
crossover (p1,p2,n1,0,0,0) = crossover (p2,p1,n1)
by Th8; ( crossover (p1,p2,0,n2,0,0) = crossover (p2,p1,n2) & crossover (p1,p2,0,0,n3,0) = crossover (p2,p1,n3) & crossover (p1,p2,0,0,0,n4) = crossover (p2,p1,n4) )
crossover (p1,p2,0,n2,0,0) = crossover (p1,p2,0,n2)
by Th30;
hence
crossover (p1,p2,0,n2,0,0) = crossover (p2,p1,n2)
by Th7; ( crossover (p1,p2,0,0,n3,0) = crossover (p2,p1,n3) & crossover (p1,p2,0,0,0,n4) = crossover (p2,p1,n4) )
crossover (p1,p2,0,0,n3,0) = crossover (p1,p2,0,n3)
by Th30;
hence
crossover (p1,p2,0,0,n3,0) = crossover (p2,p1,n3)
by Th7; crossover (p1,p2,0,0,0,n4) = crossover (p2,p1,n4)
crossover (p1,p2,0,0,0,n4) = crossover (p1,p2,0,n4)
by Th30;
hence
crossover (p1,p2,0,0,0,n4) = crossover (p2,p1,n4)
by Th7; verum