With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Newfoundland and Labrador is Canada's least linguistically homogeneous.
text_B: In mathematics , Serre and localizing subcategories form important classes of subcategories of an abelian category .. Localizing subcategories are certain Serre subcategories .. They are strongly linked to the notion of a quotient category .
not_related.