With no explanation, label text_A→text_B with either "NOT ENOUGH INFO", "REFUTES" or "SUPPORTS".
text_A: Metallica and Megadeth are rival bands .
text_B: Guitarist Dave Mustaine ( who went on to form Megadeth ) and bassists Ron McGovney , Cliff Burton and Jason Newsted are also former members of the band .
NOT ENOUGH INFO.