let n1, n2, n3, n4 be Element of NAT ; :: thesis: for S being Gene-Set
for p1, p2 being Individual of S holds
( crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n1,n2,n4,n3) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n1,n3,n2,n4) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n1,n3,n4,n2) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n1,n4,n3,n2) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n2,n1,n3,n4) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n2,n1,n4,n3) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n2,n3,n1,n4) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n2,n3,n4,n1) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n2,n4,n1,n3) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n2,n4,n3,n1) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n3,n2,n1,n4) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n3,n2,n4,n1) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n3,n4,n1,n2) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n3,n4,n2,n1) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n4,n2,n3,n1) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n4,n3,n2,n1) )

let S be Gene-Set; :: thesis: for p1, p2 being Individual of S holds
( crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n1,n2,n4,n3) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n1,n3,n2,n4) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n1,n3,n4,n2) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n1,n4,n3,n2) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n2,n1,n3,n4) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n2,n1,n4,n3) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n2,n3,n1,n4) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n2,n3,n4,n1) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n2,n4,n1,n3) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n2,n4,n3,n1) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n3,n2,n1,n4) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n3,n2,n4,n1) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n3,n4,n1,n2) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n3,n4,n2,n1) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n4,n2,n3,n1) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n4,n3,n2,n1) )

let p1, p2 be Individual of S; :: thesis: ( crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n1,n2,n4,n3) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n1,n3,n2,n4) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n1,n3,n4,n2) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n1,n4,n3,n2) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n2,n1,n3,n4) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n2,n1,n4,n3) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n2,n3,n1,n4) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n2,n3,n4,n1) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n2,n4,n1,n3) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n2,n4,n3,n1) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n3,n2,n1,n4) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n3,n2,n4,n1) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n3,n4,n1,n2) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n3,n4,n2,n1) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n4,n2,n3,n1) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n4,n3,n2,n1) )
A1: crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n1,n2,n4,n3)
proof
set q2 = crossover (p2,p1,n1,n2);
set q1 = crossover (p1,p2,n1,n2);
crossover (p1,p2,n1,n2,n3,n4) = crossover ((crossover (p1,p2,n1,n2)),(crossover (p2,p1,n1,n2)),n3,n4)
.= crossover ((crossover (p1,p2,n1,n2)),(crossover (p2,p1,n1,n2)),n4,n3) by Th13
.= crossover ((crossover ((crossover (p1,p2,n1,n2)),(crossover (p2,p1,n1,n2)),n4)),(crossover ((crossover (p2,p1,n1,n2)),(crossover (p1,p2,n1,n2)),n4)),n3) ;
hence crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n1,n2,n4,n3) ; :: thesis: verum
end;
A2: crossover (p1,p2,n1,n2,n3,n4) = crossover ((crossover (p1,p2,n1,n3,n2)),(crossover (p2,p1,n1,n2,n3)),n4) by Th25
.= crossover ((crossover (p1,p2,n1,n3,n2)),(crossover (p2,p1,n1,n3,n2)),n4) by Th25 ;
A3: crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n2,n3,n4,n1)
proof
set q2 = crossover (p2,p1,n2,n3);
set q1 = crossover (p1,p2,n2,n3);
crossover (p1,p2,n1,n2,n3,n4) = crossover ((crossover (p1,p2,n2,n1,n3)),(crossover (p2,p1,n1,n2,n3)),n4) by Th25
.= crossover ((crossover (p1,p2,n2,n3,n1)),(crossover (p2,p1,n1,n2,n3)),n4) by Th25
.= crossover ((crossover (p1,p2,n2,n3,n1)),(crossover (p2,p1,n2,n1,n3)),n4) by Th25
.= crossover ((crossover (p1,p2,n2,n3,n1)),(crossover (p2,p1,n2,n3,n1)),n4) by Th25
.= crossover ((crossover (p1,p2,n2,n3)),(crossover (p2,p1,n2,n3)),n1,n4)
.= crossover ((crossover (p1,p2,n2,n3)),(crossover (p2,p1,n2,n3)),n4,n1) by Th13
.= crossover ((crossover (p1,p2,n2,n3,n4)),(crossover (p2,p1,n2,n3,n4)),n1) ;
hence crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n2,n3,n4,n1) ; :: thesis: verum
end;
A4: crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n1,n4,n3,n2)
proof
set q2 = crossover (p2,p1,n1,n3);
set q1 = crossover (p1,p2,n1,n3);
crossover (p1,p2,n1,n2,n3,n4) = crossover ((crossover (p1,p2,n1,n3,n2)),(crossover (p2,p1,n1,n2,n3)),n4) by Th25
.= crossover ((crossover (p1,p2,n1,n3,n2)),(crossover (p2,p1,n1,n3,n2)),n4) by Th25
.= crossover ((crossover (p1,p2,n1,n3)),(crossover (p2,p1,n1,n3)),n2,n4)
.= crossover ((crossover (p1,p2,n1,n3)),(crossover (p2,p1,n1,n3)),n4,n2) by Th13
.= crossover ((crossover (p1,p2,n1,n3,n4)),(crossover (p2,p1,n1,n3,n4)),n2)
.= crossover ((crossover (p1,p2,n1,n4,n3)),(crossover (p2,p1,n1,n3,n4)),n2) by Th25
.= crossover ((crossover (p1,p2,n1,n4,n3)),(crossover (p2,p1,n1,n4,n3)),n2) by Th25 ;
hence crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n1,n4,n3,n2) ; :: thesis: verum
end;
A5: crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n4,n3,n2,n1)
proof
set q2 = crossover (p2,p1,n3,n2);
set q1 = crossover (p1,p2,n3,n2);
crossover (p1,p2,n1,n2,n3,n4) = crossover ((crossover (p1,p2,n3,n1,n2)),(crossover (p2,p1,n1,n2,n3)),n4) by Th26
.= crossover ((crossover (p1,p2,n3,n1,n2)),(crossover (p2,p1,n3,n1,n2)),n4) by Th26
.= crossover ((crossover (p1,p2,n3,n2,n1)),(crossover (p2,p1,n3,n1,n2)),n4) by Th25
.= crossover ((crossover (p1,p2,n3,n2,n1)),(crossover (p2,p1,n3,n2,n1)),n4) by Th25
.= crossover ((crossover (p1,p2,n3,n2)),(crossover (p2,p1,n3,n2)),n1,n4)
.= crossover ((crossover (p1,p2,n3,n2)),(crossover (p2,p1,n3,n2)),n4,n1) by Th13
.= crossover ((crossover (p1,p2,n3,n2,n4)),(crossover (p2,p1,n3,n2,n4)),n1)
.= crossover ((crossover (p1,p2,n4,n3,n2)),(crossover (p2,p1,n3,n2,n4)),n1) by Th26
.= crossover ((crossover (p1,p2,n4,n3,n2)),(crossover (p2,p1,n4,n3,n2)),n1) by Th26 ;
hence crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n4,n3,n2,n1) ; :: thesis: verum
end;
A6: crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n2,n1,n4,n3)
proof
set q2 = crossover (p2,p1,n2,n1);
set q1 = crossover (p1,p2,n2,n1);
crossover (p1,p2,n1,n2,n3,n4) = crossover ((crossover (p1,p2,n2,n1,n3)),(crossover (p2,p1,n1,n2,n3)),n4) by Th25
.= crossover ((crossover (p1,p2,n2,n1,n3)),(crossover (p2,p1,n2,n1,n3)),n4) by Th25
.= crossover ((crossover (p1,p2,n2,n1)),(crossover (p2,p1,n2,n1)),n3,n4)
.= crossover ((crossover (p1,p2,n2,n1)),(crossover (p2,p1,n2,n1)),n4,n3) by Th13
.= crossover ((crossover (p1,p2,n2,n1,n4)),(crossover (p2,p1,n2,n1,n4)),n3) ;
hence crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n2,n1,n4,n3) ; :: thesis: verum
end;
A7: crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n4,n2,n3,n1)
proof
set q2 = crossover (p2,p1,n2,n3);
set q1 = crossover (p1,p2,n2,n3);
crossover (p1,p2,n1,n2,n3,n4) = crossover ((crossover (p1,p2,n2,n1,n3)),(crossover (p2,p1,n1,n2,n3)),n4) by Th25
.= crossover ((crossover (p1,p2,n2,n1,n3)),(crossover (p2,p1,n2,n1,n3)),n4) by Th25
.= crossover ((crossover (p1,p2,n2,n3,n1)),(crossover (p2,p1,n2,n1,n3)),n4) by Th25
.= crossover ((crossover (p1,p2,n2,n3,n1)),(crossover (p2,p1,n2,n3,n1)),n4) by Th25
.= crossover ((crossover (p1,p2,n2,n3)),(crossover (p2,p1,n2,n3)),n1,n4)
.= crossover ((crossover (p1,p2,n2,n3)),(crossover (p2,p1,n2,n3)),n4,n1) by Th13
.= crossover ((crossover (p1,p2,n2,n3,n4)),(crossover (p2,p1,n2,n3,n4)),n1)
.= crossover ((crossover (p1,p2,n4,n2,n3)),(crossover (p2,p1,n2,n3,n4)),n1) by Th26
.= crossover ((crossover (p1,p2,n4,n2,n3)),(crossover (p2,p1,n4,n2,n3)),n1) by Th26 ;
hence crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n4,n2,n3,n1) ; :: thesis: verum
end;
A8: crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n1,n3,n4,n2)
proof
set q2 = crossover (p2,p1,n1,n3);
set q1 = crossover (p1,p2,n1,n3);
crossover (p1,p2,n1,n2,n3,n4) = crossover ((crossover (p1,p2,n1,n3,n2)),(crossover (p2,p1,n1,n2,n3)),n4) by Th25
.= crossover ((crossover (p1,p2,n1,n3,n2)),(crossover (p2,p1,n1,n3,n2)),n4) by Th25
.= crossover ((crossover (p1,p2,n1,n3)),(crossover (p2,p1,n1,n3)),n2,n4)
.= crossover ((crossover (p1,p2,n1,n3)),(crossover (p2,p1,n1,n3)),n4,n2) by Th13
.= crossover ((crossover ((crossover (p1,p2,n1,n3)),(crossover (p2,p1,n1,n3)),n4)),(crossover ((crossover (p2,p1,n1,n3)),(crossover (p1,p2,n1,n3)),n4)),n2) ;
hence crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n1,n3,n4,n2) ; :: thesis: verum
end;
A9: crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n3,n2,n4,n1)
proof
set q2 = crossover (p2,p1,n3,n2);
set q1 = crossover (p1,p2,n3,n2);
crossover (p1,p2,n1,n2,n3,n4) = crossover ((crossover (p1,p2,n3,n1,n2)),(crossover (p2,p1,n1,n2,n3)),n4) by Th26
.= crossover ((crossover (p1,p2,n3,n1,n2)),(crossover (p2,p1,n3,n1,n2)),n4) by Th26
.= crossover ((crossover (p1,p2,n3,n2,n1)),(crossover (p2,p1,n3,n1,n2)),n4) by Th25
.= crossover ((crossover (p1,p2,n3,n2,n1)),(crossover (p2,p1,n3,n2,n1)),n4) by Th25
.= crossover ((crossover (p1,p2,n3,n2)),(crossover (p2,p1,n3,n2)),n1,n4)
.= crossover ((crossover (p1,p2,n3,n2)),(crossover (p2,p1,n3,n2)),n4,n1) by Th13
.= crossover ((crossover (p1,p2,n3,n2,n4)),(crossover (p2,p1,n3,n2,n4)),n1) ;
hence crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n3,n2,n4,n1) ; :: thesis: verum
end;
A10: crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n2,n4,n1,n3)
proof
set q2 = crossover (p2,p1,n2,n1);
set q1 = crossover (p1,p2,n2,n1);
crossover (p1,p2,n1,n2,n3,n4) = crossover ((crossover (p1,p2,n2,n1,n3)),(crossover (p2,p1,n1,n2,n3)),n4) by Th25
.= crossover ((crossover (p1,p2,n2,n1,n3)),(crossover (p2,p1,n2,n1,n3)),n4) by Th25
.= crossover ((crossover (p1,p2,n2,n1)),(crossover (p2,p1,n2,n1)),n3,n4)
.= crossover ((crossover (p1,p2,n2,n1)),(crossover (p2,p1,n2,n1)),n4,n3) by Th13
.= crossover ((crossover (p1,p2,n2,n1,n4)),(crossover (p2,p1,n2,n1,n4)),n3)
.= crossover ((crossover (p1,p2,n2,n4,n1)),(crossover (p2,p1,n2,n1,n4)),n3) by Th25
.= crossover ((crossover (p1,p2,n2,n4,n1)),(crossover (p2,p1,n2,n4,n1)),n3) by Th25 ;
hence crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n2,n4,n1,n3) ; :: thesis: verum
end;
A11: crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n3,n4,n2,n1)
proof
set q2 = crossover (p2,p1,n3,n2);
set q1 = crossover (p1,p2,n3,n2);
crossover (p1,p2,n1,n2,n3,n4) = crossover ((crossover (p1,p2,n3,n1,n2)),(crossover (p2,p1,n1,n2,n3)),n4) by Th26
.= crossover ((crossover (p1,p2,n3,n1,n2)),(crossover (p2,p1,n3,n1,n2)),n4) by Th26
.= crossover ((crossover (p1,p2,n3,n2,n1)),(crossover (p2,p1,n3,n1,n2)),n4) by Th25
.= crossover ((crossover (p1,p2,n3,n2,n1)),(crossover (p2,p1,n3,n2,n1)),n4) by Th25
.= crossover ((crossover (p1,p2,n3,n2)),(crossover (p2,p1,n3,n2)),n1,n4)
.= crossover ((crossover (p1,p2,n3,n2)),(crossover (p2,p1,n3,n2)),n4,n1) by Th13
.= crossover ((crossover (p1,p2,n3,n2,n4)),(crossover (p2,p1,n3,n2,n4)),n1)
.= crossover ((crossover (p1,p2,n3,n4,n2)),(crossover (p2,p1,n3,n2,n4)),n1) by Th25
.= crossover ((crossover (p1,p2,n3,n4,n2)),(crossover (p2,p1,n3,n4,n2)),n1) by Th25 ;
hence crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n3,n4,n2,n1) ; :: thesis: verum
end;
A12: crossover (p1,p2,n1,n2,n3,n4) = crossover ((crossover (p1,p2,n3,n1,n2)),(crossover (p2,p1,n1,n2,n3)),n4) by Th26
.= crossover ((crossover (p1,p2,n3,n1,n2)),(crossover (p2,p1,n3,n1,n2)),n4) by Th26
.= crossover ((crossover (p1,p2,n3,n2,n1)),(crossover (p2,p1,n3,n1,n2)),n4) by Th25
.= crossover ((crossover (p1,p2,n3,n2,n1)),(crossover (p2,p1,n3,n2,n1)),n4) by Th25 ;
A13: crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n3,n4,n1,n2)
proof
set q2 = crossover (p2,p1,n3,n1);
set q1 = crossover (p1,p2,n3,n1);
crossover (p1,p2,n1,n2,n3,n4) = crossover ((crossover (p1,p2,n3,n1,n2)),(crossover (p2,p1,n1,n2,n3)),n4) by Th26
.= crossover ((crossover (p1,p2,n3,n1,n2)),(crossover (p2,p1,n3,n1,n2)),n4) by Th26
.= crossover ((crossover (p1,p2,n3,n1)),(crossover (p2,p1,n3,n1)),n2,n4)
.= crossover ((crossover (p1,p2,n3,n1)),(crossover (p2,p1,n3,n1)),n4,n2) by Th13
.= crossover ((crossover (p1,p2,n3,n1,n4)),(crossover (p2,p1,n3,n1,n4)),n2)
.= crossover ((crossover (p1,p2,n3,n4,n1)),(crossover (p2,p1,n3,n1,n4)),n2) by Th25
.= crossover ((crossover (p1,p2,n3,n4,n1)),(crossover (p2,p1,n3,n4,n1)),n2) by Th25 ;
hence crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n3,n4,n1,n2) ; :: thesis: verum
end;
A14: crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n2,n4,n3,n1)
proof
set q2 = crossover (p2,p1,n2,n3);
set q1 = crossover (p1,p2,n2,n3);
crossover (p1,p2,n1,n2,n3,n4) = crossover ((crossover (p1,p2,n2,n1,n3)),(crossover (p2,p1,n1,n2,n3)),n4) by Th25
.= crossover ((crossover (p1,p2,n2,n3,n1)),(crossover (p2,p1,n1,n2,n3)),n4) by Th25
.= crossover ((crossover (p1,p2,n2,n3,n1)),(crossover (p2,p1,n2,n1,n3)),n4) by Th25
.= crossover ((crossover (p1,p2,n2,n3,n1)),(crossover (p2,p1,n2,n3,n1)),n4) by Th25
.= crossover ((crossover (p1,p2,n2,n3)),(crossover (p2,p1,n2,n3)),n1,n4)
.= crossover ((crossover (p1,p2,n2,n3)),(crossover (p2,p1,n2,n3)),n4,n1) by Th13
.= crossover ((crossover (p1,p2,n2,n3,n4)),(crossover (p2,p1,n2,n3,n4)),n1)
.= crossover ((crossover (p1,p2,n2,n4,n3)),(crossover (p2,p1,n2,n3,n4)),n1) by Th25
.= crossover ((crossover (p1,p2,n2,n4,n3)),(crossover (p2,p1,n2,n4,n3)),n1) by Th25 ;
hence crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n2,n4,n3,n1) ; :: thesis: verum
end;
A15: crossover (p1,p2,n1,n2,n3,n4) = crossover ((crossover (p1,p2,n2,n1,n3)),(crossover (p2,p1,n1,n2,n3)),n4) by Th25
.= crossover ((crossover (p1,p2,n2,n1,n3)),(crossover (p2,p1,n2,n1,n3)),n4) by Th25 ;
crossover (p1,p2,n1,n2,n3,n4) = crossover ((crossover (p1,p2,n2,n1,n3)),(crossover (p2,p1,n1,n2,n3)),n4) by Th25
.= crossover ((crossover (p1,p2,n2,n1,n3)),(crossover (p2,p1,n2,n1,n3)),n4) by Th25
.= crossover ((crossover (p1,p2,n2,n3,n1)),(crossover (p2,p1,n2,n1,n3)),n4) by Th25
.= crossover ((crossover (p1,p2,n2,n3,n1)),(crossover (p2,p1,n2,n3,n1)),n4) by Th25 ;
hence ( crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n1,n2,n4,n3) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n1,n3,n2,n4) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n1,n3,n4,n2) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n1,n4,n3,n2) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n2,n1,n3,n4) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n2,n1,n4,n3) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n2,n3,n1,n4) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n2,n3,n4,n1) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n2,n4,n1,n3) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n2,n4,n3,n1) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n3,n2,n1,n4) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n3,n2,n4,n1) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n3,n4,n1,n2) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n3,n4,n2,n1) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n4,n2,n3,n1) & crossover (p1,p2,n1,n2,n3,n4) = crossover (p1,p2,n4,n3,n2,n1) ) by A2, A15, A1, A8, A4, A6, A3, A10, A14, A12, A9, A13, A11, A7, A5; :: thesis: verum