URPX Condition Model

Version: 0.5.1 Last Updated: 2026-10-05
Status: Adopted for URPX 0.4.0
Scope: Structured condition-expression modeling in eligibility, applicability, and related contexts
Ontology Source: urpx-ontology.ttl
SHACL Source: urpx-shacl.ttl

---

Introduction

This document defines the structured condition-expression model used in URPX.

The model is designed to express rule logic in a way that is:

• machine-readable,
• straightforward to validate with SHACL,
• understandable to human authors and reviewers, and
• flexible enough to support both direct property comparisons and nested derived expressions.

URPX uses the same condition-expression architecture for:

• urpx:EligibilityRule, which must carry one structured condition expression and determines qualification for a rate plan or a modifier,
• urpx:ApplicabilityRule, which determines when a price, price set, or price definition applies,
• urpx:ApplicabilityGroup, where it may be used for additional structured applicability logic, and
• urpx:ProfileAlternative, which carries exactly one structured condition expression that defines the alternative.

Design Goals

• Keep atomic predicates separate from boolean composition.
• Make the rule-level entry point explicit.
• Support direct comparisons, nested arithmetic, and derived expressions.
• Support object-valued, datatype-valued, and fallback custom operands.
• Use datatype-specific literal value properties instead of a generic mixed-type literal slot.
• Allow optional human-readable expression text without making that text authoritative for execution.

Table of Contents

• Core Modeling Pattern
• Class Reference
• Property Reference
• Supported Literal Value Properties
• Operator Sets
• Validation Summary
• JSON-LD Context Pattern
• JSON-LD Example Use Cases

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Core Modeling Pattern

URPX condition modeling separates five concerns:

1. Rule attachment
   EligibilityRule and ProfileAlternative must each attach exactly one structured condition expression through urpx:hasConditionExpression. ApplicabilityRule and ApplicabilityGroup may attach at most one.

2. Rule-level wrapper
   ConditionExpression is the rule-level wrapper. It points to exactly one urpx:rootNode.

3. Atomic predicates
   ComparisonNode expresses one independently evaluable predicate with urpx:operator, urpx:leftOperand, and urpx:rightOperand.

4. Boolean composition
   BooleanOperationNode combines comparison nodes and nested boolean-operation nodes using urpx:operandNodes.

5. Operand typing
   Operand nodes distinguish object-valued references, datatype-valued literals, and custom fallback cases.

Rule-Level Structure

The rule-level entry point is always urpx:hasConditionExpression.

In the current model, this entry point is available on EligibilityRule, ApplicabilityRule, ApplicabilityGroup, and ProfileAlternative.

ConditionExpression is not itself a boolean operator node. It provides a stable wrapper with exactly one urpx:rootNode. The root may be:

• a urpx:ComparisonNode for the single-condition case, or
• a urpx:BooleanOperationNode for grouped boolean logic.

This means a single-condition rule does not need a unary boolean wrapper. The wrapper points directly to the comparison node.

Atomic Predicate Structure

ComparisonNode represents exactly one predicate. It uses:

• urpx:operator
• urpx:leftOperand
• urpx:rightOperand

Each side may be:

• an operand node, or
• an urpx:OperationNode for nested arithmetic or derived expressions.

Boolean Composition

BooleanOperationNode is used only for boolean structure. It:

• uses urpx:operator,
• uses urpx:operandNodes,
• accepts only boolean operators, and
• does not use urpx:leftOperand or urpx:rightOperand.

Operand Node Families

URPX uses three operand-node families:

• urpx:ObjectOperandNode
• urpx:DatatypeOperandNode
• urpx:CustomOperandNode

These make the role of each operand explicit without relying on a generic terminal-node abstraction.

Datatype Handling

Datatype intent is carried by the value property used and, where relevant, by the range of the referenced ontology property.

URPX does not require a separate datatype enumeration on operand nodes. Instead, literal-bearing operand nodes use one of the datatype-specific value properties such as:

• urpx:booleanValue
• urpx:dateValue
• urpx:dateTimeValue
• urpx:decimalValue
• urpx:durationValue
• urpx:gMonthValue
• urpx:gYearValue
• urpx:integerValue
• urpx:stringValue
• urpx:timeValue

Metric Input References on Operand Nodes

urpx:referencesMetricInput is used in three distinct ways:

• On ObjectOperandNode, it can serve as the direct object-valued operand form.
• On DatatypeOperandNode, it may optionally appear on a literal-bearing operand node.
• On CustomOperandNode, it may optionally appear on a literal-bearing operand node.

For datatype and custom operand nodes, referencesMetricInput is used only when the node also carries exactly one datatype-specific literal value property. It is not used on the property-reference branch of DatatypeOperandNode, and it is not used on the customConditionProperty branch of CustomOperandNode.

Human-Readable Expression Text

urpx:logicExpression may be attached to:

• urpx:ComparisonNode
• urpx:BooleanOperationNode

This property is optional. It can help with debugging, review, or UI display, but the structured node graph remains the authoritative representation for execution and validation.

Human-Readable Metadata

ComparisonNode may include:

• urpx:name
• urpx:description

These are optional and non-semantic. They are intended for human readability, audit, and display.

---

Class Reference

Rule-Level Classes

urpx:EligibilityRule

Description: Conditions determining customer and service point qualification.

Condition Model Role: An eligibility rule uses urpx:hasConditionExpression for structured qualification logic. urpx:hasCustomerProfile and urpx:hasServicePointProfile are not part of EligibilityRule.

Relevant Properties:

Property	Cardinality	Range	Description
urpx:hasConditionExpression	1..1	urpx:ConditionExpression	Attaches the structured condition expression used for rule evaluation

urpx:ApplicabilityRule

Description: Conditions that determine when a price, price set, or price definition applies.

Condition Model Role: An applicability rule uses the same condition-expression architecture as an eligibility rule.

Relevant Properties:

Property	Cardinality	Range	Description
urpx:hasConditionExpression	0..1	urpx:ConditionExpression	Attaches the structured condition expression used for rule evaluation

urpx:ApplicabilityGroup

Description: Grouping of applicability rules applicable to prices.

Condition Model Role: An applicability group may optionally use urpx:hasConditionExpression when its applicability needs structured condition logic beyond its applicabilityLogic text.

Relevant Properties:

Property	Cardinality	Range	Description
urpx:hasConditionExpression	0..1	urpx:ConditionExpression	Attaches optional structured condition logic to the applicability group

urpx:ProfileAlternative

Description: Specific combination of dimension values representing one alternative choice.

Condition Model Role: A profile alternative uses urpx:hasConditionExpression as its defining structured condition expression.

Relevant Properties:

Property	Cardinality	Range	Description
urpx:hasConditionExpression	1..1	urpx:ConditionExpression	Attaches the defining structured condition expression for the profile alternative

Expression Classes

urpx:ConditionExpression

Description: Rule-level wrapper for a structured condition expression.

Semantic Context: ConditionExpression is the entry point for rule logic. It is not itself a boolean operator node.

Key Properties:

Property	Cardinality	Range	Description
urpx:rootNode	1..1	urpx:ComparisonNode or urpx:BooleanOperationNode	The single root of the condition-expression tree

urpx:ConditionNode

Description: Abstract superclass for nodes that may appear in a condition-expression tree.

Semantic Context: ConditionNode is a structural superclass. The concrete node types are ComparisonNode and BooleanOperationNode.

urpx:ComparisonNode

Description: Atomic comparison predicate in a condition expression.

Semantic Context: ComparisonNode represents one independently evaluable predicate.

Key Properties:

Property	Cardinality	Range	Description
urpx:operator	1..1	operator IRI	Comparison or ordered-expression operator
urpx:leftOperand	1..1	operand node or urpx:OperationNode	Left side of the comparison
urpx:rightOperand	1..1	operand node or urpx:OperationNode	Right side of the comparison
urpx:logicExpression	0..1	xsd:string	Optional human-readable expression text
urpx:name	0..1	xsd:string	Optional human-readable label
urpx:description	0..1	xsd:string	Optional explanatory text

urpx:BooleanOperationNode

Description: Boolean combinator node in a condition-expression tree.

Semantic Context: BooleanOperationNode is used for AND, OR, and NOT composition only.

Key Properties:

Property	Cardinality	Range	Description
urpx:operator	1..1	boolean operator IRI	Boolean operator for the current node
urpx:operandNodes	1..n	urpx:ComparisonNode or urpx:BooleanOperationNode	Child condition nodes
urpx:logicExpression	0..1	xsd:string	Optional human-readable expression text

urpx:OperationNode

Description: Nested expression node for arithmetic or other ordered subexpressions.

Semantic Context: OperationNode is used inside ComparisonNode when an operand must itself be computed or transformed before comparison.

Key Properties:

Property	Cardinality	Range	Description
urpx:operator	1..1	operator IRI	Arithmetic or ordered-expression operator
urpx:leftOperand	1..1	operand node or urpx:OperationNode	Left subexpression operand
urpx:rightOperand	1..1	operand node or urpx:OperationNode	Right subexpression operand

Operand Node Classes

urpx:ObjectOperandNode

Description: Operand node for object-valued properties, enumeration values, and metric-input references.

Semantic Context: ObjectOperandNode is used for object-valued property comparisons and for direct references to metric inputs inside structured expressions.

Key Properties:

Property	Cardinality	Range	Description
urpx:conditionProperty	choice form	rdf:Property	Object-valued URPX property being evaluated
urpx:referencesValue	choice form	IRI	Enumeration or other referenced object value
urpx:referencesMetricInput	choice form	urpx:MetricInput	Metric input used directly as an operand

Usage Note: SHACL constrains each ObjectOperandNode to exactly one of these three forms.

urpx:DatatypeOperandNode

Description: Operand node for datatype-valued properties and datatype literal values.

Semantic Context: DatatypeOperandNode has two structural forms:

• a property-reference form using urpx:conditionProperty, or
• a literal form using exactly one datatype-specific value property.

In the literal form, urpx:referencesMetricInput may also be present when the literal threshold or literal comparison value needs explicit metric-input context.

Key Properties:

Property	Cardinality	Range	Description
urpx:conditionProperty	property form	rdf:Property	Datatype-valued URPX property being evaluated
one datatype-specific value property	literal form	matching xsd datatype	Literal comparison value
urpx:referencesMetricInput	literal form only, optional	urpx:MetricInput	Metric input context for a literal-bearing operand node

Usage Note: SHACL constrains each DatatypeOperandNode to exactly one structural branch. The property-reference branch does not allow referencesMetricInput. Literal branches may optionally include one referencesMetricInput.

urpx:CustomOperandNode

Description: Fallback operand node for concepts not yet captured by an URPX-native property.

Semantic Context: CustomOperandNode has two structural forms:

• a custom-property form using urpx:customConditionProperty, or
• a literal form using exactly one datatype-specific value property.

In the literal form, urpx:referencesMetricInput may also be present when the literal threshold or literal comparison value needs explicit metric-input context.

Key Properties:

Property	Cardinality	Range	Description
urpx:customConditionProperty	custom-property form	xsd:string	Human-readable identifier for a custom concept
one datatype-specific value property	literal form	matching xsd datatype	Literal comparison value
urpx:referencesMetricInput	literal form only, optional	urpx:MetricInput	Metric input context for a literal-bearing operand node

Usage Note: SHACL constrains each CustomOperandNode to exactly one structural branch. The customConditionProperty branch does not allow referencesMetricInput. Literal branches may optionally include one referencesMetricInput.

---

Property Reference

Rule Attachment Properties

Property	Domain	Range / Type	Usage
urpx:hasConditionExpression	urpx:EligibilityRule, urpx:ApplicabilityRule, urpx:ApplicabilityGroup, urpx:ProfileAlternative	urpx:ConditionExpression	Attaches the structured condition expression used by the owning node
urpx:rootNode	urpx:ConditionExpression	urpx:ComparisonNode or urpx:BooleanOperationNode	Points to the single root of the expression tree

Boolean Structure Properties

Property	Domain	Range / Type	Usage
urpx:operandNodes	urpx:BooleanOperationNode	urpx:ComparisonNode or urpx:BooleanOperationNode	Child nodes used for boolean composition
urpx:operator	comparison, boolean-operation, and operation nodes	operator IRI	Shared operator property; allowed subsets depend on node type
urpx:logicExpression	urpx:ComparisonNode, urpx:BooleanOperationNode	xsd:string	Optional human-readable expression text

Ordered Expression Properties

Property	Domain	Range / Type	Usage
urpx:leftOperand	urpx:ComparisonNode, urpx:OperationNode	operand node or urpx:OperationNode	Left side of a comparison or nested expression
urpx:rightOperand	urpx:ComparisonNode, urpx:OperationNode	operand node or urpx:OperationNode	Right side of a comparison or nested expression

Operand Properties

Property	Domain	Range / Type	Usage
urpx:conditionProperty	urpx:DatatypeOperandNode, urpx:ObjectOperandNode	rdf:Property	URPX-native property being evaluated
urpx:customConditionProperty	urpx:CustomOperandNode	xsd:string	Fallback identifier when no suitable URPX-native property exists
urpx:referencesValue	urpx:ObjectOperandNode	IRI	Object or enumeration value used in a comparison
urpx:referencesMetricInput	operand-node forms where allowed	urpx:MetricInput	Metric input reference used directly as an operand or as context for a literal-bearing operand

Metadata Properties

Property	Domain	Range / Type	Usage
urpx:name	urpx:ComparisonNode and broader URPX classes	xsd:string	Optional human-readable label
urpx:description	urpx:ComparisonNode and broader URPX classes	xsd:string	Optional explanatory text

Datatype-Specific Value Properties

Property	Value Type	Usage
urpx:booleanValue	xsd:boolean	Boolean literal value
urpx:dateValue	xsd:date	Calendar date literal value
urpx:dateTimeValue	xsd:dateTime	Date-time literal value
urpx:decimalValue	xsd:decimal	Decimal literal value
urpx:durationValue	xsd:duration	ISO 8601 duration literal value
urpx:gMonthValue	xsd:gMonth	Month-of-year literal value
urpx:gYearValue	xsd:gYear	Calendar year literal value
urpx:integerValue	xsd:integer	Integer literal value
urpx:stringValue	xsd:string	String literal value
urpx:timeValue	xsd:time	Time-of-day literal value

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Supported Literal Value Properties

URPX condition expressions use datatype-specific literal value properties rather than a generic mixed-type literal slot.

Datatype is conveyed by the value property itself. For example:

• urpx:integerValue carries an integer literal,
• urpx:decimalValue carries a decimal literal,
• urpx:dateValue carries a calendar date literal.

This approach keeps authoring and validation straightforward:

• authors use the value property that matches the intended datatype,
• SHACL constrains operand nodes to exactly one literal-value branch, and
• no separate datatype enumeration is required on the operand node.

---

Operator Sets

Boolean Operators

BooleanOperationNode uses boolean operators only:

• urpx:andOperator
• urpx:orOperator
• urpx:notOperator

Comparison and Ordered Expression Operators

ComparisonNode and OperationNode use the broader operator set. Common operators include:

Category	Operators
Comparison	urpx:equalsOperator, urpx:notEqualsOperator, urpx:greaterThanOperator, urpx:greaterThanOrEqualOperator, urpx:lessThanOperator, urpx:lessThanOrEqualOperator
Arithmetic	urpx:addOperator, urpx:subtractOperator, urpx:multiplyOperator, urpx:divideOperator

Boolean composition should be modeled with BooleanOperationNode, not with arithmetic or ordered-expression nodes.

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Validation Summary

URPX SHACL defines the condition model as a set of closed node shapes. In practice, that means each major node accepts only the properties appropriate to its role.

Core Expression Shapes

• EligibilityRule must carry exactly one urpx:hasConditionExpression.
• EligibilityRule does not use urpx:hasCustomerProfile or urpx:hasServicePointProfile.
• ApplicabilityRule and ApplicabilityGroup may each carry at most one urpx:hasConditionExpression.
• ProfileAlternative must carry exactly one urpx:hasConditionExpression.
• ConditionExpression requires exactly one urpx:rootNode.
• ComparisonNode requires exactly one urpx:operator, exactly one urpx:leftOperand, and exactly one urpx:rightOperand.
• BooleanOperationNode requires exactly one boolean urpx:operator.
• BooleanOperationNode uses urpx:operandNodes rather than urpx:leftOperand and urpx:rightOperand.
• BooleanOperationNode uses operator-specific cardinality:
  • urpx:andOperator requires two or more operands,
  • urpx:orOperator requires two or more operands,
  • urpx:notOperator requires exactly one operand.
• OperationNode requires exactly one urpx:operator, exactly one urpx:leftOperand, and exactly one urpx:rightOperand.

Operand Node Shapes

• ObjectOperandNode must use exactly one of:
  • urpx:conditionProperty
  • urpx:referencesValue
  • urpx:referencesMetricInput
• DatatypeOperandNode must use exactly one structural branch:
  • property-reference branch: urpx:conditionProperty
  • literal branch: exactly one datatype-specific value property, with optional urpx:referencesMetricInput
• CustomOperandNode must use exactly one structural branch:
  • custom-property branch: urpx:customConditionProperty
  • literal branch: exactly one datatype-specific value property, with optional urpx:referencesMetricInput

Practical Modeling Notes

• Use ObjectOperandNode when the comparison is naturally object-valued or enumeration-valued.
• Use DatatypeOperandNode when the comparison centers on datatype-valued properties and literal thresholds.
• Use CustomOperandNode only when no suitable URPX-native property exists.
• Use logicExpression as supplemental human-readable text only.

---

JSON-LD Context Pattern

Datatype-specific value properties are compact in JSON-LD because their coercion is declared once, in the published context, rather than per document.

Example Context

{
  "@context": "https://urpx.org/ns/context/releases/v0.5.1/jsonld/urpx-context.jsonld"
}

Note on Decimals

Write urpx:decimalValue literals as quoted strings, as the examples on this page do. A JSON number lands as a floating-point literal that the shapes reject even under xsd:decimal coercion; the tutorial and every test case follow the same rule.

---

JSON-LD Example Use Cases

Single Atomic Condition

{
  "@type": "urpx:ConditionExpression",
  "urpx:rootNode": {
    "@id": "ex:condition-customer-kind"
  }
}

{
  "@id": "ex:condition-customer-kind",
  "@type": "urpx:ComparisonNode",
  "urpx:logicExpression": "hasCustomerKind = residentialKind",
  "urpx:operator": { "@id": "urpx:equalsOperator" },
  "urpx:leftOperand": {
    "@type": "urpx:ObjectOperandNode",
    "urpx:conditionProperty": { "@id": "urpx:hasCustomerKind" }
  },
  "urpx:rightOperand": {
    "@type": "urpx:ObjectOperandNode",
    "urpx:referencesValue": { "@id": "urpx:residentialKind" }
  }
}

Two Conditions Combined With AND

{
  "@id": "ex:eligibility-expression-1",
  "@type": "urpx:ConditionExpression",
  "urpx:rootNode": {
    "@type": "urpx:BooleanOperationNode",
    "urpx:logicExpression": "customer kind is residential AND usage exceeds threshold",
    "urpx:operator": { "@id": "urpx:andOperator" },
    "urpx:operandNodes": [
      { "@id": "ex:condition-customer-kind" },
      { "@id": "ex:condition-usage-threshold" }
    ]
  }
}

Integer Threshold

{
  "@id": "ex:condition-usage-threshold",
  "@type": "urpx:ComparisonNode",
  "urpx:operator": { "@id": "urpx:greaterThanOperator" },
  "urpx:leftOperand": {
    "@type": "urpx:ObjectOperandNode",
    "urpx:referencesMetricInput": { "@id": "ex:mi-average-monthly-usage" }
  },
  "urpx:rightOperand": {
    "@type": "urpx:DatatypeOperandNode",
    "urpx:integerValue": 500,
    "urpx:referencesMetricInput": { "@id": "ex:mi-average-monthly-usage" }
  }
}

Derived Decimal Comparison With OperationNode

The two metric inputs are defined in the version's PlanElements with units chosen so that the quotient is a ratio.

{
  "@id": "ex:condition-load-factor",
  "@type": "urpx:ComparisonNode",
  "urpx:operator": { "@id": "urpx:greaterThanOperator" },
  "urpx:leftOperand": {
    "@type": "urpx:OperationNode",
    "urpx:operator": { "@id": "urpx:divideOperator" },
    "urpx:leftOperand": {
      "@type": "urpx:ObjectOperandNode",
      "urpx:referencesMetricInput": { "@id": "ex:mi-energy" }
    },
    "urpx:rightOperand": {
      "@type": "urpx:ObjectOperandNode",
      "urpx:referencesMetricInput": { "@id": "ex:mi-demand" }
    }
  },
  "urpx:rightOperand": {
    "@type": "urpx:DatatypeOperandNode",
    "urpx:decimalValue": "0.4"
  }
}

Custom Fallback Comparison

{
  "@id": "ex:condition-legacy-segment",
  "@type": "urpx:ComparisonNode",
  "urpx:operator": { "@id": "urpx:equalsOperator" },
  "urpx:leftOperand": {
    "@type": "urpx:CustomOperandNode",
    "urpx:customConditionProperty": "Customer Segment Code From Legacy System"
  },
  "urpx:rightOperand": {
    "@type": "urpx:CustomOperandNode",
    "urpx:stringValue": "SEG-A"
  }
}

Unary NOT

{
  "@type": "urpx:ConditionExpression",
  "urpx:rootNode": {
    "@type": "urpx:BooleanOperationNode",
    "urpx:operator": { "@id": "urpx:notOperator" },
    "urpx:operandNodes": [
      { "@id": "ex:condition-is-cca-customer" }
    ]
  }
}

{
  "@id": "ex:condition-is-cca-customer",
  "@type": "urpx:ComparisonNode",
  "urpx:operator": { "@id": "urpx:equalsOperator" },
  "urpx:leftOperand": {
    "@type": "urpx:DatatypeOperandNode",
    "urpx:conditionProperty": { "@id": "urpx:isCCACustomer" }
  },
  "urpx:rightOperand": {
    "@type": "urpx:DatatypeOperandNode",
    "urpx:booleanValue": true
  }
}

Rule Attachment Example

{
  "@id": "ex:eligibility-rule-1",
  "@type": "urpx:EligibilityRule",
  "urpx:hasConditionExpression": {
    "@type": "urpx:ConditionExpression",
    "urpx:rootNode": {
      "@type": "urpx:BooleanOperationNode",
      "urpx:operator": { "@id": "urpx:andOperator" },
      "urpx:operandNodes": [
        { "@id": "ex:condition-customer-kind" },
        { "@id": "ex:condition-usage-threshold" }
      ]
    }
  }
}

Expanded ConditionExpression Tree

The following Mermaid diagram shows the same full structure at a glance before the complete JSON-LD serialization.

Full End-to-End ConditionExpression Graph

The examples above show individual parts of the model. The following JSON-LD example shows one complete ConditionExpression graph in a single document, including the owning EligibilityRule, the ConditionExpression, the boolean root node, and the comparison nodes embedded directly in urpx:operandNodes.

The same graph pattern can also be attached to ApplicabilityRule, ApplicabilityGroup, or ProfileAlternative. The metric input the threshold reads, ex:mi-average-monthly-usage, is included as the last node.

{
  "@context": [
    "https://urpx.org/ns/context/releases/v0.5.1/jsonld/urpx-context.jsonld",
    { "ex": "https://example.org/conditions/" }
  ],
  "@graph": [
    {
      "@id": "ex:eligibility-rule-1",
      "@type": "urpx:EligibilityRule",
      "urpx:name": "Residential usage threshold eligibility",
      "urpx:hasConditionExpression": { "@id": "ex:eligibility-expression-1" }
    },
    {
      "@id": "ex:eligibility-expression-1",
      "@type": "urpx:ConditionExpression",
      "urpx:rootNode": {
        "@id": "ex:eligibility-root-1",
        "@type": "urpx:BooleanOperationNode",
        "urpx:logicExpression": "customer kind is residential AND average monthly usage exceeds 500",
        "urpx:operator": { "@id": "urpx:andOperator" },
        "urpx:operandNodes": [
          {
            "@id": "ex:condition-customer-kind-1",
            "@type": "urpx:ComparisonNode",
            "urpx:logicExpression": "hasCustomerKind = residentialKind",
            "urpx:operator": { "@id": "urpx:equalsOperator" },
            "urpx:leftOperand": {
              "@type": "urpx:ObjectOperandNode",
              "urpx:conditionProperty": { "@id": "urpx:hasCustomerKind" }
            },
            "urpx:rightOperand": {
              "@type": "urpx:ObjectOperandNode",
              "urpx:referencesValue": { "@id": "urpx:residentialKind" }
            }
          },
          {
            "@id": "ex:condition-usage-threshold-1",
            "@type": "urpx:ComparisonNode",
            "urpx:logicExpression": "mi-average-monthly-usage > 500",
            "urpx:operator": { "@id": "urpx:greaterThanOperator" },
            "urpx:leftOperand": {
              "@type": "urpx:ObjectOperandNode",
              "urpx:referencesMetricInput": { "@id": "ex:mi-average-monthly-usage" }
            },
            "urpx:rightOperand": {
              "@type": "urpx:DatatypeOperandNode",
              "urpx:integerValue": 500,
              "urpx:referencesMetricInput": { "@id": "ex:mi-average-monthly-usage" }
            }
          }
        ]
      }
    },
    {
      "@id": "ex:mi-average-monthly-usage",
      "@type": "urpx:MetricInput",
      "urpx:name": "Average monthly usage",
      "urpx:metricInputType": { "@id": "urpx:calculatedMetricInput" },
      "urpx:hasMetricSpecification": {
        "@type": "urpx:MetricSpecification",
        "urpx:commodity": { "@id": "urpx:electricity" },
        "urpx:measurementKind": { "@id": "urpx:energy" },
        "urpx:unitOfMeasure": { "@id": "urpx:kWh" },
        "urpx:intervalDuration": "P1M",
        "urpx:hasCalculationMethod": {
          "@type": "urpx:CalculationMethod",
          "urpx:aggregationMethod": { "@id": "urpx:average" },
          "urpx:intervalDuration": "P12M"
        }
      }
    }
  ]
}