Orbits and cells for for F4 (compact) G=F4(compact) G^v=F4(split) type: F4 sc s real form: 0 dual real form: 2 G: 1--2=>=3--4 G^v: 1--2=<=3--4 Duality of orbits and cells for F_4(split)/F_4(split) Number following diagram is number of real forms A=A(O) or A(O)/Abar(O) if Abar(O)\ne A(O) A^v=A(O^v) and Abar(O^v) similarly Special Special Orbit Cells Diagram #R A Dual Orbit Cells Diagram #R A 0 24(trivial) 0000 1 1 F4 0 2222 1 1