constraint_eqn_064 Subroutine

   subroutine constraint_eqn_064(tmp_cc, tmp_con, tmp_err, tmp_symbol, tmp_units)
      !! Upper limit on Zeff
      !! author: P B Lloyd, CCFE, Culham Science Centre
      !! args : output structure : residual error; constraint value;
      !! residual error in physical units; output string; units string
      !! Upper limit on Zeff
      !! #=# physics
      !! #=#=# fzeffmax, zeffmax
      !! and hence also optional here.
      !! Logic change during pre-factoring: err, symbol, units will be assigned only if present.
      !! fzeffmax : input real : f-value for maximum zeff
      !! zeffmax : input real : maximum value for Zeff
      !! zeff : input real : plasma effective charge
      use constraint_variables, only: fzeffmax, zeffmax
      use physics_variables, only: zeff
      implicit none
            real(dp), intent(out) :: tmp_cc
      real(dp), intent(out) :: tmp_con
      real(dp), intent(out) :: tmp_err
      character(len=1), intent(out) :: tmp_symbol
      character(len=10), intent(out) :: tmp_units

      tmp_cc = 1.0D0 - fzeffmax * (zeffmax/zeff)
      tmp_con = zeffmax
      tmp_err = zeffmax * tmp_cc
      tmp_symbol = '<'
      tmp_units = ''

   end subroutine constraint_eqn_064