<math> <apply> <forall/> <bvar><ci> a </ci></bvar> <apply><and/> <apply><lt/> <apply><minus/> <apply><ceiling/> <ci>a</ci> </apply> <cn>1</cn> </apply> <ci>a</ci> </apply> <apply><leq/> <ci>a</ci> <apply><ceiling/> <ci>a</ci> </apply> </apply> </apply> </apply> </math>