let n2, n3, n1 be Element of NAT ; for S being Gene-Set
for p1, p2 being Individual of S st n2 >= len p1 & n3 >= len p1 holds
crossover p1,p2,n1,n2,n3 = crossover p1,p2,n1
let S be Gene-Set; for p1, p2 being Individual of S st n2 >= len p1 & n3 >= len p1 holds
crossover p1,p2,n1,n2,n3 = crossover p1,p2,n1
let p1, p2 be Individual of S; ( n2 >= len p1 & n3 >= len p1 implies crossover p1,p2,n1,n2,n3 = crossover p1,p2,n1 )
assume that
A1:
n2 >= len p1
and
A2:
n3 >= len p1
; crossover p1,p2,n1,n2,n3 = crossover p1,p2,n1
crossover p1,p2,n1,n2,n3 = crossover p1,p2,n1,n3
by A1, Th19;
hence
crossover p1,p2,n1,n2,n3 = crossover p1,p2,n1
by A2, Th10; verum