constraint_eqn_037 Subroutine

   subroutine constraint_eqn_037(tmp_cc, tmp_con, tmp_err, tmp_symbol, tmp_units)
      !! Equation for current drive gamma upper limit
      !! author: P B Lloyd, CCFE, Culham Science Centre
      !! args : output structure : residual error; constraint value;
      !! residual error in physical units; output string; units string
      !! Equation for current drive gamma upper limit
      !! #=# current_drive
      !! #=#=# fgamcd, gammax
      !! and hence also optional here.
      !! Logic change during pre-factoring: err, symbol, units will be assigned only if present.
      !! fgamcd : input real : f-value for current drive gamma
      !! gammax : input real : maximum current drive gamma
      !! gamcd : input real : normalised current drive efficiency (1.0e20 A/W-m2)
      use constraint_variables, only: fgamcd, gammax
      use current_drive_variables, only: gamcd
      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 - fgamcd * gammax/gamcd
      tmp_con = gammax * (1.0D0 - tmp_cc)
      tmp_err = gamcd * tmp_cc
      tmp_symbol = '<'
      tmp_units = '1E20 A/Wm2'

   end subroutine constraint_eqn_037