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Equation Numbering & Referencing

The core feature of LaTeX Equation Referencer is automatic equation numbering using LaTeX \tag{} commands and smart referencing via internal links.

How Equation IDs Work

Unlike Obsidian's built-in block references (^block-id after content), this plugin uses LaTeX comments inside math blocks:

$$
E = mc^2
% id: eq-einstein
$$

The % id: eq-einstein comment:

  • Is invisible in rendered output (it's a LaTeX comment)
  • Creates a unique identifier for the equation
  • Must use the format eq- followed by alphanumeric characters and hyphens
  • Must be on its own line before the closing $$

Automatic Numbering

When an equation has an ID and is referenced somewhere in the note, the plugin automatically inserts a \tag{} command:

Before (what you write): 

$$
E = mc^2
% id: eq-einstein
$$

See equation [[#^eq-einstein]].

After (what the plugin generates): 

$$
E = mc^2 \tag{1}
% id: eq-einstein
$$

See equation [[#^eq-einstein]].

Number Only Referenced Equations

By default, equations are only numbered if they're referenced somewhere. This can be changed in settings.

Number Styles

Configure the numbering style in plugin settings:

Style Example Output
arabic 1, 2, 3, ...
alph a, b, c, ...
Alph A, B, C, ...
roman i, ii, iii, ...
Roman I, II, III, ...

Prefix and Suffix

Add custom text before/after equation numbers:

Setting Value Result
Prefix: § - (§1)
Suffix: . - (1.)
Prefix: Eq. - (Eq.1)

Sub-Equations

For multi-line equations, reference individual lines using sub-indices:

$$
a &= b + c \\
d &= e + f
% id: eq-system
$$

First equation: [[#^eq-system-1]]
Second equation: [[#^eq-system-2]]

The plugin generates:

  • \tag{1.1} for the first row
  • \tag{1.2} for the second row

Referencing Equations

Using Autocomplete

  1. Type your trigger string (default: \eqref)
  2. A suggestion popup appears with all equations in the current note
  3. Select an equation using arrow keys or mouse
  4. Press Enter to insert [[#^eq-id]]

Jump to Equation

Hold the modifier key (default: Ctrl/Cmd) while pressing Enter on a suggestion to jump to the equation instead of inserting a link.

Reference Display Format

Configure how equation links are displayed:

Setting Display Format
Show note title: ON Note Title > (1)
Show note title: OFF (1)
Reference prefix: Eq. Eq.(1)
Reference suffix: none (1)

Live Preview vs Reading View

The plugin works in both Obsidian views:

  • Live Preview: Uses CodeMirror extensions for real-time numbering
  • Reading View: Uses Markdown post-processors for rendered output

Both views stay synchronized - editing in one updates the other.

Equation Cache

The plugin maintains a cache of all equations in the current note for fast lookup. This cache is:

  • Built when a note is opened
  • Updated on every document change
  • Used for autocomplete suggestions and hover previews