ANN Traing with 6 input and 2 output optimal with Ga or Gamultiobj

Dear Sir,

(1) I read a lot of Q&A from Matlab website,I get a conclusion : ga only can optimal 1 output , Is it right? If my output is 2 should I try gamultiobj?

(2) If only can use gamultiobj ,can u give me some ANN optimal with gamultiobj example matlab code for my Ref ?

(3) I read some thesis , for my case : 6 input x1:x6 and 2 output y1:y2, if i can write down 2 or three eq. or more eq. For example : y1=x1^2+x1*x2*5-x2*x3*4.......;

y2=x2^2+x4*x5*6+...., give the upper bounds and lower bounds for x1:x6 ,running gamultiobj ,it can get some input and output also

(4) if I am forcus on ANN (beacuse it can be predict y),what the difference between method 2 (ANN optimal with gamultiobj )and method 3(regression eq +gamultiobj )?

Hope u can teach me and answer , thanks

Terry