Gravar-mail: 5-[(E)-4-Fluoro­benzyl­idene]-8-(4-fluoro­phen­yl)-2-hy­droxy-9-phenyl-3,10-diaza­hexa­cyclo­[10.7.1.1(3,7).0(2,11).0(7,11).0(16,20)]henicosa-1(20),12,14,16,18-pentaen-6-one