t_31 :: (real ~ "1" on
         (i = 0 .. nlon + 1 by
          j = 0 .. nlat + 1 by
          k = 1 .. nlev
         )
        )


CSE Eliminated

t_31 := ( varidx(hxt, [i, j])
        * varidx(hyt, [i, j])
        * (varidx(p, [i, j, k + 1]) - varidx(p, [i, j, k]))
        )