---
type: "term"
title: "Parallel Operator (+)"
description: "Notation that denotes concurrent (or effectively concurrent) steps—actions that occur in the same phase where their ordering is not meaningful."
resource: "tlctc:term:parallel-operator"
tags:
  - "glossary"
---
# Parallel Operator (+)

Notation that denotes **concurrent** (or effectively concurrent) steps—actions that occur in the same phase where their ordering is not meaningful. Parallel steps MUST be grouped using parentheses: `(#X + #Y)`. Each element inside a parallel group is a separate Attack Step mapped to exactly one cluster.

**Reference:** §4.2.2 (Global Definitions), §11.2 (Parallel Operator)