According to Diestel (page 4): "If $G' \subseteq G$ and $G'$ contains all the edges $xy \in E$ with $x, y \in V'$, then $G'$ is an induced subgraph of $G$"
According to Wikipedia "induced cycle is a cycle that is an induced subgraph of $G$; induced cycles are also called cordless cycles "
Does the definition by Diestel imply induced cycles are chordless?
In this graph, does induced subgraph $G[\{a,b,c,d\}]$ include edge $ac$?
Both $a$ and $c$ are in $V'$.