How to express a more complex constraint in Mata?

[Nicolas Larrea]

Hello! I have a minimization problem with 5 parameters to be estimated: miu[1], miu[2], sigma[1], sigma[2] and pb[1].

The restriction I need to introduce in my code is:

pb[1]*miu[1] + (1-pb[1])*miu[2] = 0

I've tried to express it this way:

C = (miu[1]-miu[2], 0, 1, 0, 0)
c = (0)
Cc = (C, c)
optimize_init_constraints(S, Cc)

However, when I run it, STATA replies: "<istmt>: 3499 miu not found"

What am I doing wrong?

Thanks!