How to define coefficient c in 3 coupling pdes in solving 2D-PDE (PDE toolbox)

I'm solving 2D-pdes using PDE toolbox, my problem is how to define coefficient c because the third equation (below) is coupled with A and B. I have tried a lot with pde toolbox and refer to this link, but failed to identify c coefficient.

https://www.mathworks.com/help/pde/ug/c-coefficient-for-systems-for-specifycoefficients.html#bu5tm4f-1

According to this link, I can easily define the first equation and column vector c (first 2 rows), c(1) = c(4) = c, c(2) = c(3) = 0; but I have no idea how to define c in the third equation. Could anybody give me some help?

Answer 1

[Ravi Kumar]

If you have Symbolic Math Toolbox, then you can use the pdeCoefficients function to get the requried c-coefficient.

Regards,

Ravi

[Yue]

It's useful. Thank you very much!