anchor.diff:      goto 160
   !-----------------------------------------------------------------------
   !  QUADRUPOLE
  -!  FOCUSSING
  +!  FOCUSING
   !-----------------------------------------------------------------------
   80  do j=1,napx
         fok = ekv(j,l)*oidpsv(j)
  
positive.code:       as(4,ih1,j,l) = as4+(two*as6)*fok1
        as(5,ih1,j,l) = (as6*fok1**2-(rvv(j)*sm12)/(c4e3*rho**2))+fok1*as4
        as(6,ih1,j,l) = as6
  !--VERTIKAL
        g  = tan_mb(fok*half)/rho
        gl = el(l)*g
        al(1,ih2,j,l) = one-gl
  
negative.code:         as(4,1,j,l) = (((-one*rvv(j))*al(2,1,j,l))*al(3,1,j,l))/c2e3
          as(5,1,j,l) = (((-one*rvv(j))*(el(l)-al(1,1,j,l)*al(2,1,j,l)))*aek)/c4e3
          as(6,1,j,l) = ((-one*rvv(j))*(el(l)+al(1,1,j,l)*al(2,1,j,l)))/c4e3
  !--DEFOCUSING
          hp = exp_mb(fi)
          hm = one/hp
          hc = (hp+hm)*half
  