if equation with initial() as condition causes rightless error

[Jens Frenkel]

The following model causes an rightless IF_EQUATION_UNBALANCED_2 error. 

model A
    Real x;
    Real y;
    parameter Real a=3;
equation
    der(x) + x = y;
    y = time;
    if initial() then
      x = a;
      x = 1;
   end if;
end A;
 

Error: If-equation with conditions that are not parameter expressions must have the same number of equations in
each branch, equation count is {2,0} for each respective branch.

 

[Willi Braun]

But initial() is not constant while the simulation time, so that model is invalid and error is correct.

[Martin Sjölund]

No, Modelica has special rules for if initial(), which changes the equation into an initial equation (I believe).

[Martin Sjölund]

It works now (if you remove one of the equations as it said x=a=3=1...)