For fixed z and a=7/2, b>=a
For fixed z and a=7/2, b=7/2
For fixed z and a=7/2, b=4
For fixed z and a=7/2, b=9/2
For fixed z and a=7/2, b=5
For fixed z and a=7/2, b=11/2
For fixed z and a=7/2, b=6