If I understand correctly, an "EQUATIVE" verb considers equally among nouns, which is the subject, and which is the predicate noun. In other words, they equally qualify for either position in a sentence. If, for example, I were to say "My Uncle is the President of the company for which I work;" "Uncle" and "President" would equally qualify as the subject, and equally qualify as the Predicate Noun. That is the only application of "Equate" that applies to the nouns.
Is this a correct understanding?
In your example sentence, "My uncle" is the subject. The word "is" is the verb. (It is an equative verb here.)
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