anchor.diff:    return
   end subroutine
   
  -subroutine vel_update_vort
  +subroutine compute_omega
     use state
     use posvel
     use forces
  
positive.code:   deallocate(voz)
  
    return
  end subroutine
  
  
  ! ===================================== !
  ! One step of SPH                       !
  ! ===================================== !
  subroutine step
    use constants, only : ITERATIONS_PER_STEP
    implicit none
    integer :: subiter
  
  
negative.code: subroutine computePressureRadiusFactor
    use constants
    implicit none
    real(WP) :: r, c
  
    r = ARTIFICIAL_PRESSURE_RADIUS
    c = 315.0_WP / (64.0_WP * PI)
  
    PRESSURE_RADIUS_FACTOR = 1.0_WP / &
      (c * (KERNEL_SIZE*KERNEL_SIZE - r*r)**3 &
  