for SAS being AffinPlane st SAS is Desarguesian holds
for o, a, a9, b, b9, c, c9 being Element of SAS st not o,a // o,b & not o,a // o,c & o,a // o,a9 & o,b // o,b9 & o,c // o,c9 & a,b // a9,b9 & a,c // a9,c9 holds
b,c // b9,c9