This file preview is blocking the kitchen’s JavaScript, so the shapes cannot be added here. Download the HTML file and open it in Chrome or Safari to use the board.
Ingredients
tap tap tap, drag to move
Pick a few shapes, let them meet, and toast a region.
Union keeps anything in at least one selected shape. Intersection keeps only what all selected shapes share. A second bake lets you group an earlier result with a new shape: (A ∪ B) ∩ C.
This drawing only shades two-dimensional regions: an intersection made solely of a point or a line will appear as ∅, even though the mathematical intersection is nonempty.
Every ingredient includes its boundary. Union and intersection preserve closedness. Minus uses the closure of the set difference, so cut edges remain included. Every baked region remains closed.