Reveal an aligned derivation, line by line
Stack several equation lines with every "=" aligned, and reveal them one at a time.
Show several steps of a derivation at once, stacked and aligned, revealed one line at a time.
When this is the right tool (vs. derivation)
Both mathtex (with lines) and derivation walk through a sequence of algebraic states, but they show that sequence differently:
derivationmorphs ONE equation through successive states — each step replaces the last on screen, matched tokens sliding to their new position. Good for "watch this exact expression rearrange."- A
mathtexwithlineskeeps every prior line visible, stacked below the one before it, with every=lined up vertically — the classic worked-proof layout. Good for "here's the full chain of reasoning, all still on screen."
If you want the classic "line 1, then line 2 appears below it, then line 3…" board-work look, use this. See Build a step-by-step equation derivation for the morph-in-place alternative.
Set up the lines
- Add a
mathtexobject (or open the Formula editor on an existing one). - In Lines (one LaTeX per line, 2+ to enable), write each line of the proof, one per row. For example:
would be three lines: 2x + 3 = 11, 2x = 8, x = 4. The first = on each line becomes the alignment point automatically — you don't write the & yourself.
mathtex has always worked. The aligned block only kicks in once you've entered 2 or more lines.Reveal them one at a time
Once 2+ lines are set, a Lines shown field and a ◆ keyframe diamond appear. Keyframe it the same way as any other property — record mode or the ◆ diamond — and each integer boundary the playhead crosses reveals one more line via TransformMatchingTex, the same token-matching morph derivation's step uses. Leaving Lines shown unset (or dragging it to the last line) just shows the whole block at once, with no reveal animation.
Color a specific term
Turn on Color parts (set_color_by_tex) to recolor a specific substring everywhere it appears in the equation — useful for drawing the eye to the same term as it carries through several lines of a derivation. Add a substring (e.g. x, or \sin\theta) and a color; it compiles to set_color_by_tex(...), layered on top of the object's own fill color. This works whether or not Lines is in use — it's a plain per-part recolor on any mathtex object.
See Objects → Formula — mathtex for the exact field reference.