Boxes and structure

The box is the basic building block. A box with a label is a single line:

Give shapes names (identifiers) so you can refer to them later. A name goes before a colon:

Lines starting with // are comments and are ignored when rendering:

A box sizes itself to its label, but you can set an explicit width or height. Unpositioned boxes flow left to right, and gap sets the space before a box in that flow:

Next: connect boxes with Arrows and flow.