Expression Language (EL) v LANG 1.0.0

This document describes the openEHR Expression Language (EL). The EL defines a syntax and grammar which may be considered the default syntax for the openEHR Basic Meta-Model (BMM).

Within openEHR, EL can be used to express:

· pre-, post-conditions and class invariants in BMM model definition files

· rules in archetypes

· rules in openEHR Guideline Definition Language (GDL)

· expressions within decision logic models (DLMs) designed for use with openEHR Task Planning.

The intended audience includes standards bodies producing health informatics standards, academic groups using openEHR, and solution vendors.

Main sections:

· Overview

· EL Basics

· Terminal entities

· Complex expressions