With no explanation, label text_A→text_B with either "not-entailed" or "entailed".
text_A: Since then , most of the refugees have returned to Rwanda , but several thousand remained in the neighboring Democratic Republic of the Congo ( DRC ; the former Zaire ) and formed an extremist insurgency bent on retaking Rwanda , much as the RPF tried in 1990 .
text_B: 1990 is a calendar year
entailed.