Coefficient functions are defined as list of constants/functions. Each element corresponds to a sub-domain, or a boundary condition number.
define coefficient coef_lam 10,15, -5, (5*x), (sin(y)),
Functions must be put into brackets. Function may be built as described in Section 3.1, but may now additionally contain variables.
Predefined variables are , , and for the Cartesian coordinates.
Specifying too many coefficients is ok, too less will lead to an error.
Note: Now, the coordinates are , , and , will change to , , and .