With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Ivan Lendl is a tennis player.
text_B: Ethereal means pertaining to ether , the air or the sky .. It may also refer to  :. Ethereal -LRB- horse -RRB- , a horse that won Australia 's Caulfield and Melbourne Cups in 2001. Wireshark , formerly named Ethereal , a software network traffic analyzer. Wireshark. Wireshark. Ethereal wave , a music genre also often referred to simply as ` ethereal '. Ethereal wave. Ethereal wave
not_related.