“…I 1 is the operator set, where {*, /,sin,cos,exp, log} F r and { , } T x R are function and terminal sets. *, /, sin, cos, exp, rlog, x, and R denote the multiplication, protected division ( x, y R : when y = 0, x/0 = 1), sine, cosine, exponent, protected logarithm ( x R, x 0 : rlog(x) = log(abs(x)) and rlog(0) = 0), system inputs, and random constant number, taking 2, 2, 1, 1, 1, 1, 0 and 0 arguments respectively [18]. According to the specific problems, we could add some complex functions into operator set I 1 , for example 11 {*, /,sin, cos, log, tan, , , ,*3,*4, , } 111…”