XML structure and namespaces

Every RBlang document starts with the XML declaration and the root knowledge base element.

<?xml version="1.0" encoding="utf-8"?>
<rbl:kb xmlns:rbl="http://rbl.io/schema/RBLang">
    <!-- knowledge base content -->
</rbl:kb>

Required structure

• <?xml version="1.0" encoding="utf-8"?>

• <rbl:kb> as the root element

• xmlns:rbl="http://rbl.io/schema/RBLang" on the root element

Use UTF-8 encoding.

The xmlns:rbl namespace is required.

Recommended definition order

Define elements in this order:

1. Concepts

2. Relationships

3. Concept instances for string concepts

4. Relationship instances and rules

Core elements

RBlang uses these core elements:

• <concept> for concept definitions

• <rel> for relationship definitions

• <concinst> for string concept instances

• <relinst> for facts and rules

• <condition> for rule conditions

Skeleton template

<?xml version="1.0" encoding="utf-8"?>
<rbl:kb xmlns:rbl="http://rbl.io/schema/RBLang">
    <concept name="Person" type="string"/>
    <concept name="Age" type="number"/>

    <rel name="has age" subject="Person" object="Age"/>

    <concinst name="John Smith" type="Person"/>
    <relinst type="has age" subject="John Smith" object="25"/>
</rbl:kb>

Type naming in RBlang

RBlang uses the type name truth for boolean concepts.

<concept name="Is Eligible" type="truth"/>