E)$ be a cubic graph with chromatic index 4 and $c:E→{1
2
3
4}$ a proper 4-edge-coloring.Let $E-i={e∈E｜c(e)=i}$ and $o(c)=%min%{｜E-i｜｜i=1
2
3
4}.$ Denote by $C(G)$ all the proper 4-edge-colorings of $G$ and $m(G)= %min% [DD(X] c∈C(G) {o(c)}$ is defined to be the color-character of $G.$ In this paper
we prove that $m(G)$ is a constant under the $Δ-$reduction.
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references
BONDY J A, MURTY U S R. Graph Theory with Applications[M]. Lordon: Macmillan Press Ltd, 1976. 91-96.
WATKINS J J, WILSON. A survey of snarks[A].In:Alavi et al Y. Graph theory, Combinatorics and Application [C].New York: Wiley, 1991:1 129-1 144.
ISAACS R. Infinite families of non-trivial trivalent graphs which are not Tait colorable[J]. Am Math Monthly, 1975 82:221-239.
STEFFEN E. Classification and characterizations of snarks[J]. Discrete Math,1998,188:183-203.
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