@Markiyan Hirnyk 

Followed up the file.

At the end, I just want to define a new paramter (Y) that is equal to the value of x1a...

Hope now it will be more clear.

model_for_mapleprime.mw

model_for_mapleprime.mw

Followed up the file.

I just want to dfine a new paramter (Y) that is equal to the value of x1a...

Hope now it will be moer clear. 

I'll try again:

By using the DirectSearch package, the results of 4 polynomial equations are:

> DirectSearch[SolveEquations](sys, assume = positive);
Warning, complex or non-numeric value encountered; trying to find a feasible point
        [HFloat(1.1842542076623546e-32),

          Vector[column](%id = 18446744078126621390), [

          x1a = HFloat(4204.651582462925),

          x1c = HFloat(4204.651582462925),

          x2a = HFloat(1787.760621851102),

          x2c = HFloat(1787.7606218511032)], 392]

Now, i want define a new parameter Y, that is equale to x1a, meaning that Y=4204.651, without using CtrlC+CtrlV...

i tried with defining Y=x1a but it didnt work.

Thanks

Gil

i will try again:

assume that the results of rhe directsearch are:

> DirectSearch[SolveEquations](sys, assume = positive);
Warning, complex or non-numeric value encountered; trying to find a feasible point
        [HFloat(1.1842542076623546e-32), 

          Vector[column](%id = 18446744078126621390), [

          x1a = HFloat(4204.651582462925), 

          x1c = HFloat(4204.651582462925), 

          x2a = HFloat(1787.760621851102), 

          x2c = HFloat(1787.7606218511032)], 392]

"

Now, i want to define a new x1a (let call it x1a1)  that is value is x1a1=x1a+y meaning x1a1=4204.651+y

meanwhile I copy the value of x1a th the eqquation by using CtrlC + CtrlV

Gil