Li Zhang, Hajo Broersma, You Lu, Shenggui Zhang
A graph G is edge-$k$-choosable if, for any assignment of lists $L(e)$ of at least $k$ colors to all edges $e\in E(G)$, there exists a proper edge coloring such that the color of $e$ belongs to $L(e)$ for all $e\in E(G)$. One of Vizing's classic conjectures asserts that every graph is edge-$(\Delta+1)$-choosable. It is known since 1999 that this conjecture is true for general graphs with $\Delta\leq4$. More recently, in 2015, Bonamy confirmed the conjecture for planar graph with $\Delta\geq8$, but the conjecture is still open for planar graphs with $5\leq\Delta\leq7$. We confirm the conjecture for planar graphs with $\Delta\ge 6$ in which every 7-cycle (if any) induces a $C_7$ (so, without chords), thereby extending a result due to Dong, Liu and Li.