Reader Syntax Entry: Dotted Pair

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Reader Syntax Entry: Dotted Pair

Name

Dotted Pair

Class

Reader Syntax

Concrete Syntax

dotted-pair ::= "(" expression "." expression ")"

Description

A dotted pair is a two-part cons-style representation written with a dot separator.

Acceptance Rules

  • used heavily in association lists and entity data

Strict/Lax Policy

  • strict and lax modes agree for ordinary dotted-pair syntax

Examples

  • (A . 2)
  • (8 . "WALLS")

Compatibility

Language-central across AutoCAD and BricsCAD.

Notes

Dotted pairs are semantically more important in AutoLISP than in many other Lisp environments because of CAD data conventions.

Availability

  • AutoCAD 2026: documented (per Autodesk reference page).
  • BricsCAD V26: presumed compatible (no contradicting page found).
  • Status: AutoCAD documented; BricsCAD presumed-both pending Phase 4 verification.