~得る (formal potential)

The formal/literary modal auxiliary ~得る (read うる or える), 'can X / be able to X / is possible to X.' Attaches to a verb's masu-stem: ありうる ('is possible'), 起こりうる ('can occur'), 考え得る ('can be thought'), なりえる ('can become'), 言いうる ('can be said'). Derives from the classical 得 ('obtain'); in modern Japanese it survives chiefly in set written expressions.