I am adding the program to calculate zero's using Newton's Method, I was wondering what the significance of 2 commands are when putting them in. the whole string is:

N+1>N:X-y1(x)/y2(x)>x:{N,X,Y1(x)}

I was wondering what these two commands actually meant in terms of application of newton's method.

1) N+1>N

2) {N,X,Y1(x)}

Thanks in advance.