numeric gen_sigma; gen_sigma=1;
     
def dim_sigma = 9.5u#,x_height#,0 enddef;
def ital_sigma = 0 enddef;
def fit_params_sigma = 0,.75u# enddef;
     
def mid_sigma=
italcorr ital_sigma; adjust_fit(fit_params_sigma);
if known pic.c: currentpicture:=pic.c; else: gen_mid_sigma; fi
if not working_hard : picture pic.c; pic.c=currentpicture; fi
enddef;
     
def gen_mid_sigma =
  pickup fine.nib;
  lft x4r=hround .75u; rt x8r=w-lft x4r;        %left and right bulge
  top y2r=h; bot y6r=-oo; x2r=x6r;              %top and bottom
  numeric fake; fake=y2r-(vstem-currentbreadth); %approx height of z2l
  2y4r=y2r+y6r; 2y8r=fake+y6r;
  (x8r-x6r)/(y8r-y6r)=-(x4r-x6r)/(y4r-y6r);     %determine x6r
  y1r=y2r;rt x1=hround(rt x8r+u); pos1(flare,90);       %tip
  filldraw stroke z1e..gr_arc.e(2,3,4)(vstem,curve,otilt)
    & gr_arc.e(4,5,6)(vair,curve,otilt)         %top stroke and left bowl
    & gr_arc.e(6,7,8)(vair,curve,otilt);        %bottom part of right bowl
  z9l=z2l; pos9(vair,180); z9'l=z2'l; z9'r=left;
  filldraw stroke z8e{z8'e}..z9e{z9'e};         %top part of right bowl
enddef;