Ardith Hinton:

>   In   general  the  article  may  be  omitted  when  some
>   individual's  name  is  mentioned  first  &  a  bit   of
>   clarification  is  added  almost  immediately...  either
>   separated by a comma, as above, or at times by the  verb
>   "[to be]":
>
>     Justin Trudeau is [the] Prime Minister of Canada.
>     Susan Smith is [the] General Manager of the XYZ Company.

I  might  further  help  Alexander by adding that in Russian
these nouns would be inflected.   The  article  is  required
when the noun is not inflected and is the subject of a verb.

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