«إما أن يكون العدد زوجا أو فردا»
Either the number is even or it is odd.
The first alternative, “The number is even,” is categorical, and so is the second, “The number is odd.” The disjunctive connector either … or relates these two complete claims.
Identifying just the nouns “even” and “odd” does not fully explain the structure. Each side is a proposition about the number, and the whole forms the first type of composite disjunction.