This class represents an Earley item [ <i>A</i> → α • β, <i>j</i> ], which means that α has been recognized since the construction of the Earley set denoted by <i>j</i>. <p> Predecessor links as well as causal links between items are added to be able to reconstruct a derivation. Each item of the form [ <i>A</i> → α <i>X</i> • γ, <i>j</i> ] is linked to a predecessor [ <i>A</i> → α • <i>X</i> γ, <i>j</i> ]. Furthermore, each item of the form [ <i>A</i> → α <i>B</i> • γ, <i>j</i> ] is linked to an item [ <i>B</i> → β •, <i>k</i> ] by which it has been added in the completer step.