Dependency Parsing 2D: Arc-Standard Shift-Reduce Parser

This is the flat, panel-based twin of the 3D dependency-parser simulator: the same arc-standard transition system — a stack of partially-processed words, a buffer of words still waiting to be read, and the three moves SHIFT, LEFT-ARC, RIGHT-ARC — rendered instead as three synchronized 2D canvases. The main stage draws the sentence with dependency arcs curving into place above it (pan by dragging, scale with the zoom slider); a dedicated stack panel and buffer panel mirror the parser's live internal state below, and a transition log records every move as it happens. Step through the oracle one transition at a time or auto-run it across five example sentences, and confirm for yourself that every projective tree here takes exactly 2n − 1 transitions to build.