obsolete 3,4-dihydroxy-3,4-dihydrofluorene dehydrogenase activity (obsolete GO:0034790)
OBSOLETE. Catalysis of the reaction: (+)-(3S,4R)-cis-3,4-dihydroxy-3,4-dihydrofluorene = 3,4-dihydroxyfluorene + 2 H+ + 2 e-.