Math Variables

Variable types

Variables are auto-detected when you write definitions and expressions.

BLOCK

Defined by a written expression (e.g. x=3). Read-only in the variable canvas — change the expression on canvas to update.

API_GLOBAL

Set via ≡ → Math → Edit Variables. Global fallback — used when no BLOCK definition exists for that name.

API

Set programmatically per block. Takes priority over everything else.

UNDEFINED

Referenced in an expression but not yet defined. Set a value via Edit Variables to resolve.

Priority order

When the same variable name exists in multiple scopes:

1. API

Highest — per-block programmatic value overrides all.

2. BLOCK

Written expression on the canvas.

3. API_GLOBAL

Global fallback — only used if no BLOCK definition exists.

Try it

Substitution

Write x=5, then write 3x+2=. Computation uses x=5 automatically.

Chained variables

Write x=3 and y=x+1. Then write y²=. Result chains through both definitions.

Updating a BLOCK variable

Write x=2, then x²= (result 4). To change x, erase the "2" and write 5 in its place — a BLOCK variable's value is defined by the ink itself, so it's read-only in Edit Variables (and can't be overridden via the API either); editing the canvas is the only way. The dependent expression recalculates automatically (result becomes 25).

Global fallback

Write 2x= without defining x first. Open ≡ → Math → Edit Variables → add x=10 → Apply. Compute → result 20. Now write x=3 next to it — BLOCK x=3 wins, result becomes 6.

Undefined variable

Write A+B= without defining them. They appear as UNDEFINED in Edit Variables. Assign values there to resolve.

Tips

BLOCK variables update when you modify the expression on canvas. Use API_GLOBAL for constants shared across the page (e.g. A=42) when you don't want to write them as ink.