For fixed z and with symbolical integers in parameters

For fixed z and a=n, b=+-m

For fixed z and a=-n, b=+-m

For fixed z and a=1/2+-n, b=m

For fixed z and a=1/2+-n, b=-m

For fixed z and a=-n, b=1/2+-m

For fixed z and a=n, b=1/2+-m

For fixed z and a=n+1/2, b=m+1/2

For fixed z and a=n+1/2, b=1/2-m

For fixed z and a=1/2-n, b=m+1/2

For fixed z and a=1/2-n, b=1/2-m