0$ڥ$f$œڢ 0$ڢڕڥ$f$œڐ$G$ڤڢڢڡڢ \english >\special{em:linewidth 0.4pt} >\unitlength 1.00mm >\linethickness{0.4pt} >\begin{picture}(43.25,22.92) >\emline{2.00}{11.67}{1}{12.00}{21.67}{2} >\emline{12.00}{21.67}{3}{32.00}{1.67}{4} >\emline{32.00}{1.67}{5}{42.00}{11.67}{6} >\emline{42.00}{11.67}{7}{32.00}{21.67}{8} >\emline{32.00}{21.67}{9}{12.00}{1.67}{10} >\emline{12.00}{1.67}{11}{2.00}{11.67}{12} >\put(2.00,11.67){\circle*{1.60}} >\put(22.00,11.67){\circle*{1.60}} >\put(42.00,11.34){\circle*{1.60}} >\put(32.00,21.67){\circle*{1.60}} >\put(32.00,1.67){\circle*{1.60}} >\put(12.00,1.67){\circle*{1.60}} >\put(12.00,21.67){\circle*{1.60}} >\end{picture} >\farsi $$\ech(H)=\Chi'(H)\le\Chi'(G)<\ech(G)$$ <ڐڐɤ$G$$\ech$œڐڕړɓڟrefCLCC׊$G$ <$\Chi'$œڐڐ$uv$ڢڢ$G$ړڢ <$\Chi'(G\setminus uv)=\Chi'(G)-1$$\ech(G\setminus uv)=\ech(G)-1$ <گڟڤړ$G\setminus uv$ڢڐړڢ <$\ech(G)-1=\Chi'(G)-1$ڐړړڟڤړ$G$ <ڢ