Help with NGCGUI routine

(pyngcgui: FEATURE 140323:16.44.42)
(pyngcgui: files: </home/marius/dev/bluearc/nc_files/ngcgui_lib/lathe/lathe_mm.ngc,/home/marius/dev/bluearc/nc_files/ngcgui_lib/lathe/seal_a.ngc,>)
(pyngcgui: feature line added) #<_feature:> = 0
(pyngcgui: preamble file: /home/marius/dev/bluearc/nc_files/ngcgui_lib/lathe/lathe_mm.ngc)
g18 (xz plane)
g21 (mm)
g40 (cancel cutter radius compensation)
g49 (cancel tool lengthoffset)
g90 (absolute distance mode)
g94 (units/min feedrate)
g54 (Coordinate system 1 default)
#<tol>  = 0.001
g64 p#<tol> (path control stop)
(Positional parameters for /home/marius/dev/bluearc/nc_files/ngcgui_lib/lathe/seal_a.ngc)
        #1 = 50
        #2 = 50
        #3 = 20
        #4 = 22
        #5 = 1
        #6 = 1
        #7 = 1
        #8 = 1
        #9 = 10
        #10 = 1
        #11 = 1
        #12 = 80
        #13 = 20
        #14 = 1500
        #15 = 2
        #16 = 2
(expanded file: /home/marius/dev/bluearc/nc_files/ngcgui_lib/lathe/seal_a.ngc)
            ; Author: Marius Liebenberg
            (info: Complete seal turning - lathe)
                  #<Stock_Dia> = #1 (=50 Stock Size)
                        #<OD> =  #2 (=50 OD-Outside Diameter)
                  #<Hole_Dia> =  #3 (=20 Hole size)
                        #<ID> =  #4 (=22 ID-Inside Diameter)
                        #<S0> =  #5 (=1 S0-Width Outside Slot)
                        #<S1> =  #6 (=1 S1-Width Inside Slot)
                        #<D0> =  #7 (=1 D0-Depth Outside Slot)
                        #<D1> =  #8 (=1 D1-Depth Inside Slot)
                          #<W> = #9 (=10 W-Width of Seal)
                          #<C> = #10 (=1 C-Width of chamfer)
                   #<Depth_Cut>= #11 (=1 Cut Size)
              #<SurfaceSpeed> =  #12 (=80 Surface Speed)
                  #<FeedRate> =  #13 (=20 Feed mmPM)
            #<MaxSpindle_RPM> =  #14 (=1500 MAX RPM)
                        #<T1W> = #15 (=2 Tool 1 width)
                        #<T2W> = #16 (=2 Tool 2 Width)
            ;#<left:> =  #<_hal[twincontrol.select-lh]> 
            ;#<right> = #<_hal[twincontrol.select-rh]>
            (Probe here first)
            ;o<if00> if [[#<left> eq 1] and [#<right> eq 1]]
            ;						o<probe_both> call
            ;				else if [#<left> eq 1]
            ;						o<probe_left> call
            ;				else if [#<right> eq 1]
            ;						o<probe_right> call
            ;o<if00> endif
            #<Z_StartOfCut> = 0.5
            ;T#<ToolNumber> M6
            ; G43: toollength offset
            ; G7:  diameter mode
            ; G96: constant surface speed
            ;G43 G7 G96 D#<MaxSpindle_RPM> S#<SurfaceSpeed>
            ; Turn the ID
            M3 ;M#<Coolant> ; spindle cw, coolant on/off:w
            ; Turn the ID
            G0 X#<Hole_Dia> Z#<Z_StartOfCut>
            #<Current-Diameter> = #<Hole_Dia>
            #<Final_Dia>  = #<ID>
            ;;;;;; I am trying to invert the W variable to be negative here ???
            #<Z_EndOfCut> = [[#<W> * [-1]] - 1]
            o100 while [#<Hole_Dia> lt #<ID>]
            O101   if [#<Current-Diameter> + #<Depth_Cut> lt #<ID>]
                     #<Current-Diameter> = [#<Current-Diameter> + #<Depth_Cut>]
            O101   else
                     #<Current-Diameter> = #<ID>
            O101   endif
                   X#<Current-Diameter>
                   G1 Z#<Z_EndOfCut> F#<FeedRate>
                   G0 X[#<Current-Diameter>-1]
                   Z#<Z_StartOfCut>
            o100 endwhile
            o102 while [#<Spring_Cuts> gt 0]
                   G1 X#<ID>
                   Z#<Z_EndOfCut>
                   X[#<ID>-1]
                   G0 Z#<Z_StartOfCut>
                   #<Spring_Cuts> = [#<Spring_Cuts> -1]
            o102 endwhile
            G0 X[#<Current-Diameter> + 1]
            ;Now cut the OD
            G0 X#<Stock_Size> Z#<Z_StartOfCut>
            #<Current-Diameter> = #<Stock_Size>
            o200 while [#<Current-Diameter> gt #<OD>]
            O201   if [#<Current-Diameter> - #<Depth_Cut> gt #<OD>]
                     #<Current-Diameter> = [#<Current-Diameter> - #<Depth_Cut>]
            O201   else
                     #<Current-Diameter> = #<OD>
            O201   endif
                   X#<Current-Diameter>
                   G1 Z#<Z_EndOfCut> F#<FeedRate>
                   G0 X[#<Current-Diameter>+1]
                   Z#<Z_StartOfCut>
            o200 endwhile
            o202 while [#<Spring_Cuts> gt 0]
                   G1 X#<OD>
                   Z#<Z_EndOfCut>
                   X[#<OD>+1]
                   G0 Z#<Z_StartOfCut>
                   #<Spring_Cuts> = [#<Spring_Cuts> -1]
            o202 endwhile
            G0 X[#<Current-Diameter>+1]
            M5 M9             ; stop spindle, all coolant off
            Z#<Z_StartOfCut>
            G49               ; cancel tool length offset
            G53 G0 X0 Z0      ; move in machine coordinates
            ;pyngcgui ignoring: m2
(pyngcgui: m2 line added) m2 (g54 activated)

o100 while [#<Current_Diameter> lt #<ID>]
                o101   if [#<Current_Diameter> + #<Depth_Cut> lt #<ID>]
                     #<Current_Diameter> = [#<Current_Diameter> + #<Depth_Cut>]
                o101   else
                     #<Current_Diameter> = #<ID>
                o101   endif
                X#<Current_Diameter>
                G1 Z#<Z_EndOfCut> F#<FeedRate>
                G0 X[#<Current_Diameter>-1]
                Z#<Z_StartOfCut>
o100 endwhile