将abc=1代入三个分数,则可得出：a/(ab +a+1)=a/(ab +a+abc)=a/a(b+1+bc)=1/b+1+bc
b/(bc +b+1)= b/(bc +b+abc)=b/b(c+1+ac)=1/c+1+ac
c/(ac +c+1)=c/(ac +c+abc)=c/c(a+1+ab)=1/a+1+ab