Greedy, Top-k, and the Tree

The Decode Tree

The decode tree collects the greedy path and the top-k branches. It is computed from the displayed logits and tie-break.

highlighted = computed this step

The decode tree

The tree shows the greedy path and the top-k branches for the two displayed steps. Every branch comes from exact logit ordering.

tree from exact selections\text{tree from exact selections}
Decode treeGreedy path with top-k branches.Decode treeGreedy path with top-k branches.exact greedy path with top-k branchestree choices are exact argmax/top-k selections from displayed logitsstartstep 1choose aa=3, b=1, c=2top1: atop2: cstep 2choose ba=0, b=4, c=1top1: btop2: cgreedy decode: a,b

Greedy path

The selected path is a then b. The first step keeps top-k branches a and c; the second step keeps b and c.

a→ba\rightarrow b
Decode treeGreedy path with top-k branches.Decode treeGreedy path with top-k branches.exact greedy path with top-k branchestree choices are exact argmax/top-k selections from displayed logitsstartstep 1choose aa=3, b=1, c=2top1: atop2: cstep 2choose ba=0, b=4, c=1top1: btop2: cgreedy decode: a,b

Summary

The tree is deterministic for the shown logits, top-k value, and tie-break. It is a structural view of the same exact choices.

greedy path plus top-k branches\text{greedy path plus top-k branches}
Decode treeGreedy path with top-k branches.Decode treeGreedy path with top-k branches.exact greedy path with top-k branchestree choices are exact argmax/top-k selections from displayed logitsstartstep 1choose aa=3, b=1, c=2top1: atop2: cstep 2choose ba=0, b=4, c=1top1: btop2: cgreedy decode: a,b