Figure 5.

Level 1 assembly. Initially only the red glues on the Initiation and Junction Tiles are active and strong enough to bind tiles together (Step 1). The arrow configuration on the blue edge is set up so that it cannot yet bind to itself. Binding sends a signal across the Junction Tile to activate the blue glue on the other side (Step 2). The light gray arrow is replaced by double arrow markings from the original Robinson tile set to indicate that this event has occurred. Once active, four pairs of tiles can come together to form a square shape (Step 3). The central green glue is strong enough to recruit a Decision Tile only after the square has formed (Step 4). Binding of the central green Decision Tile causes signals to be sent in all four directions along the Junction Tiles. The signals sent give these tiles their identity, (indicated by the replacement of all remaining light gray arrows by single or double arrows from the original Robinson tile sets), and activate new binding glues on the perimeter of the level 1 square (Step 5). The strongest active glue becomes the only relevant one in later steps of assembly, therefore we only show the relevant color at the edge of a fixed tile.