MathSpacer
Explicit glue with a signed logical advance. Negative advance moves the next item left while the spacer's physical width stays nonnegative.
| Property | Default | Meaning |
|---|---|---|
| advance | em(0) | A signed length, or thin, medium, thick, quad, or qquad. |
| height | px(0) | Optional logical height for a strut. |
| axis | Half the height | Math-axis position from the top; may lie outside the box. |
Common font, color, and sizing properties follow Gum units. Math preserves separate logical advance, outline ink, baseline, and math-axis guides. See math authoring for supported TeX and font setup.