corners: varpi = 0.01286664705882353  delta = 1e-08  -> OK
corners: varpi = 0.01286764605882353  delta = 1e-11  -> OK
corners: varpi = 0.0125  delta = 1e-06  -> OK
corners: varpi = 0.01  delta = 1e-06  -> OK
corners: varpi = 0.001  delta = 1e-06  -> OK
varpi = 0.01286664705882353  delta = 1e-08  xi1 = 0.35020724352941174  xi2 = xi3 = 0.40440578470588234  -> OK
varpi = 0.01286764605882353  delta = 1e-11  xi1 = 0.3501838469494118  xi2 = xi3 = 0.40441175872588236  -> OK
varpi = 0.01265  delta = 1e-08  xi1 = 0.3552984494117647  xi2 = xi3 = 0.4031059023529412  -> OK
Meeting point: 1/4+12w = 4/9-28w/9 at w = 7/544 ; xi2 = 55/136
Interval for xi1 at the limit: ( 0.3400735294117647 , 0.3602941176470588 )
1/(1/4+7/544) = 544/143 = 3.804195804195804
  with c1 <= 6.7e-06 : 544/(143(1-c1)) = 3.8042212924784637
  with c1 <= 2e-05 : 544/(143(1-c1)) = 3.804271889633597
RESULTAT : OK