st: how to calculate a new variable subtracting from an original value a unit every time a condition is satisfied

[Raffaele Palladino <palladino.raffaele@gmail.com>]

Dear statalist users,

                             I am dealing with the following problem:
I have to calculate a variable that expresses how many people of the
family are living together. I have a variable that says how many
people compose the family (family_number) and several variables
(member1, 2 etc) that express whether the person is still living in
that family or not (they goe from 1 which means that the member still
lives in, to 5, all the others mean different conditions, all
expressing that the member is living elsewhere).
I would need to calculate a new variable which is basically equal to
family_number but that also subtracts a unit every time one of the
variables member* is not equal to 1 (there are missing values as well
in the dataset). Is there a way to obtain it?
thank you in advance
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