
= ∑a(b-c)²【(1-2a)²{56a²bc+a[a²(32b²+15bc+32c²)+17abc(b+c)+98b²c²]
+ abc[28a³+4a²(b+c)+8a(8b²+bc+8c²)+45bc(b+c)]
+ 4b²c²[19a³+13bc(b+c)]+16b³c³[a(b+c)+b²+bc+c²]}
+ abc〔8a+13bc+19bc(b+c)+12bc(b²+c²)
+ 4bc[a(7b²+26bc+7c²)+(b+c)(12b²+25bc+12c²)]
+ bc{32a²(b²+c²)+16(b²+3bc+c²)[a(b+c)+2b²+bc+2c²]}〕】≥0.