obsolete 3,4-dihydroxyfluorene 4,4-alpha-dioxygenase activity (obsolete GO:0018562)
OBSOLETE. Catalysis of the reaction: 3,4-dihydroxyfluorene + O2 = 2-hydroxy-4-(1-oxo-1,3-dihydro-2H-inden-2-ylidene) but-2-enoic acid.