ISO 13584-20:1998

INTERNATIONAL ISO
STANDARD 13584-20
First edition
1998-07-01
Industrial automation systems and
integration — Parts library —
Part 20:
Logical resource: Logical model of expressions
Systèmes d'automatisation industrielle et intégration — Bibliothèque de
composants —
Partie 20: Ressource logique: Modèle logique d'expressions
A
Reference number
ISO 13584-20:1998(E)

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ISO 13584-20:1998(E)
Page
Contents
Foreword .vi
Introduction . viii
1 Scope . 1
2 Normative references. 1
3 Terms and definitions. 2
3.1 Terms and definitions from ISO 10303-11 . 2
3.2 Terms and definitions from ISO 10303-44 . 2
3.3 Other terms and definitions. 3
4 Abbreviated terms . 5
5 Fundamental concepts and assumptions. 6
5.1 Static and dynamic data. 6
5.2 Syntax of expressions. 6
5.3 Semantics of expressions . 6
5.3.1 Semantic of expressions. 6
5.3.2 Exchange time and evaluation time . 6
5.4 Levels of abstraction in expression modelling . 7
5.4.1 Specialisation of the ISO13584_generic_expressions_schema. 7
5.4.2 Specialisation of the ISO13584_expressions_schema. 7
5.5 Modelling a variable . 7
5.5.1 Syntactic representation . 7
5.5.2 Domain of values for a variable .8
5.5.3 Semantics of a variable. 8
5.6 Mappability to the SQL language. 8
6 ISO13584_generic_expressions_schema .8
6.1 Introduction . 8
6.2 ISO13584_generic_expressions_schema entity definitions . 9
6.2.1 Generic_expression. 9
6.2.2 Simple_generic_expression. 10
6.2.3 Generic_literal. 10
6.2.4 Generic_variable. 10
6.2.5 Variable_semantics. 11
6.2.6 Environment. 11
6.2.7 Unary_generic_expression . 11
6.2.8 Binary_generic_expression. 12
6.2.9 Multiple_arity_generic_expression. 12
6.3 ISO13584_generic_expressions_schema function definitions . 12
6.3.1 Is_acyclic function. 13
6.3.2 Used_variables function. 14
©  ISO 1998
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any
means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the publisher.
International Organization for Standardization
Case postale 56 • CH-1211 Genève 20 • Switzerland
Internet iso@iso.ch
Printed in Switzerland
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©ISO
ISO 13584-20:1998(E)
7 ISO13584_expressions_schema . 15
7.1 Introduction . 15
7.2 ISO13584_expressions_schema overall entity definitions. 16
7.2.1 Expression . 16
7.2.1.1 Variable. 16
7.2.1.2 Defined_function.17
7.2.1.3 SQL_mappable_defined_function . 17
7.3 ISO13584_expressions_schema : entity definitions for numeric expressions. 17
7.3.1 Numeric_expression . 17
7.3.2 Simple_numeric_expression. 18
7.3.3 Literal_number . 18
7.3.4 Int_literal . 19
7.3.5 Real_literal . 19
7.3.6 Numeric_variable. 19
7.3.7 Int_numeric_variable. 20
7.3.8 Real_numeric_variable . 20
7.3.9 Unary_numeric_expression . 20
7.3.10 Binary_numeric_expression. 21
7.3.11 Multiple_arity_numeric_expression. 21
7.3.12 Length_function . 21
7.3.13 Value_function . 22
7.3.14 Int_value_function. 22
7.3.15 Numeric_defined_function . 23
7.3.16 Plus_expression. 23
7.3.17 Minus_expression. 23
7.3.18 Mult_expression. 24
7.3.19 Div_expression . 24
7.3.20 Mod_expression. 24
7.3.21 Slash_expression. 25
7.3.22 Power_expression . 25
7.3.23 Unary_function_call . 25
7.3.24 binary_function_call . 26
7.3.25 Multiple_arity_function_call. 26
7.3.26 Abs_function . 26
7.3.27 Minus_function. 27
7.3.28 Sin_function . 27
7.3.29 Cos_function. 28
7.3.30 Tan_function . 28
7.3.31 Asin_function . 28
7.3.32 Acos_function . 29
7.3.33 Exp_function . 29
7.3.34 Log_function . 29
7.3.35 Log2_function . 30
7.3.36 Log10_function . 30
7.3.37 Square_root_function. 31
7.3.38 Atan_function . 31
7.3.39 Maximum_function. 31
7.3.40 Minimum_function. 32
7.3.41 Integer_defined_function .32
7.3.42 Real_defined_function . 32
7.4 Boolean_expression. 33
7.4.1 Simple_boolean_expression. 33
7.4.2 Boolean_literal . 34
7.4.3 Boolean_variable . 34
7.4.4 Unary_boolean_expression . 34
7.4.5 Not_expression. 34
7.4.6 Odd_function. 35
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7.4.7 Binary_boolean_expression. 35
7.4.8 Multiple_arity_boolean_expression. 36
7.4.9 Xor_expression. 36
7.4.10 Equals_expression. 37
7.4.11 And_expression . 37
7.4.12 Or_expression. 37
7.4.13 Comparison_expression . 38
7.4.14 Comparison_equal. 39
7.4.15 Comparison_greater . 39
7.4.16 Comparison_greater_equal . 39
7.4.17 Comparison_less . 40
7.4.18 Comparison_less_equal . 40
7.4.19 Comparison_not_equal. 40
7.4.20 Like_expression. 41
7.4.21 Interval_expression. 41
7.4.22 Boolean_defined_function . 42
7.5 String_expression . 43
7.5.1 Simple_string_expression.43
7.5.2 String_literal . 43
7.5.3 String_variable . 44
7.5.4 Index_expression. 44
7.5.5 Substring_expression . 45
7.5.6 Concat_expression . 46
7.5.7 Format_function. 46
7.5.8 String_defined_function . 47
7.6 Functions to determine properties of the expression. 47
7.6.1 Is_int_expr . 48
7.6.2 Is_SQL_mappable . 50
7.6.3 Used_functions . 53
Annex A (normative) Short names of entities. 56
Annex B (normative) Information object registration.58
B.1 Document identification. 58
B.2 Schema identification. 58
B.2.1 ISO13584_generic_expressions_schema. 58
B.2.2 ISO13584_expressions_schema. 58
Annex C (informative) EXPRESS-G diagrams. 59
Annex D (informative) Use of the ISO13584_expressions_schema. 73
D.1 Introduction. 73
D.2 Interpretation function and variable semantics. 73
D.3 Representation of the interpretation function in ISO 13584 Part 20 . 73
D.4 Use of the variable_semantics entity to define the semantic of new variables. 74
D.4.1 Use of a particular subtype of the variable_semantics entity . 74
D.4.2 Multiple inheritance of the variable_semantics entity and of another entity . 75
D.4.3 Defining a concept not represented in the model. 77
Annex E (informative) Specialisation of the schemata. 78
E.1 Introduction . 78
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E.2 Specialisation of the ISO13584_generic_expressions_schema. 78
E.3 Specialisation of the ISO13584_expressions_schema. 78
E.4 Methodology for specialisation of ISO 13584 part 20 . 79
E.5 Example of specialisation of the ISO13584_generic_expressions_schema schema. 80
E.6 Example of specialisation of the ISO13584_expressions_schema schema . 82
Annex F (informative) Static analysis of expressions . 83
F.1 Introduction . 83
F.2 is_acyclic function. 83
F.3 Used_variables and used_functions functions. 83
F.4 Is_SQL_mappable function. 84
F.5 Type control and type synthesis . 84
Index . 85
Figures
Figure D.1 — Syntax and semantics association for variables. 74
Figure D.2 — Specialisation of the semantics by subtyping of the variable_semantics entity. 75
Figure D.3 — Specialisation of the semantics by subtyping the variable_semantics entity
and another entity . 76
Figure D.4 — Example of the definition of a concept not represented in the model : coordinates . 77
Table
Table A.1 — Short names of entities . 56
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©ISO
ISO 13584-20:1998(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organisations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO
collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardisation.
Draft International Standards adopted by the technical committees are circulated to the member
bodies for voting. Publication as an International Standard requires approval by at least 75 % of the
member bodies casting a vote.
International Standard ISO 13584-20 was prepared by Technical Committee ISO/TC 184, Industrial
automation systems and integration, Subcommittee SC 4, Industrial data.
ISO 13584 consists of the following parts, under the general title Industrial automation systems and
integration — Parts library:
— Part 1: Overview and fundamental principles
— Part 10: Conceptual description: Conceptual model of parts library
— Part 20: Logical resource: Logical model of expressions
— Part 24: Logical resource: Logical model of supplier library
— Part 26: Logical resource: Supplier identification
— Part 31: Implementation resource: Geometric programming interface
— Part 42: Description methodology: Methodology for structuring part families
— Part 101: View exchange protocol: Geometric view exchange protocol by parametric program
— Part 102: View exchange protocol: View exchange protocol by ISO 10303 conforming
specification
The structure of ISO 13584 is described in ISO 13584-1. The numbering of the parts of ISO 13584
reflects its structure:
— Parts 10 to 19 specify the conceptual descriptions,
— Parts 20 to 29 specify the logical resources,
— Parts 30 to 39 specify the implementation resources,
— Parts 40 to 49 specify the description methodology,
— Parts 50 to 59 specify the conformance testing,
— Parts 100 to 199 specify the view exchange protocol,
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ISO 13584-20:1998(E)
— Parts 500 to 599 specify the standardised content.
Should further parts of ISO 13584 be published, they will follow the same numbering pattern.
Annexes A and B form an integral part of this part of ISO 13584. Annexes C, D, E and F are for
information only.
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©ISO
ISO 13584-20:1998(E)
Introduction
ISO 13584 is an International Standard for the computer-interpretable representation and exchange of
part library data. The objective is to provide a neutral mechanism capable of transferring parts library
data, independent of any application that is using a parts library data system. The nature of this
description makes it suitable not only for the exchange of files containing parts, but also as a basis for
implementing and sharing databases of parts library data.
ISO 13584 is organised as a series of parts, each published separately. The parts of ISO 13854 fall
into one of the following series: conceptual descriptions, logical resources, implementation resources,
description methodology, conformance testing, view exchange protocol, and standardised content.
The series are described in ISO 13584-1. This part of ISO 13584 is a member of the logical resources
series.
This part of ISO 13584 provides the general purpose EXPRESS resource constructs needed for
expression modelling. These EXPRESS resource constructs are intended to be detailed in other parts
of ISO 13584. They are also intended to be used outside ISO 13584 wherever EXPRESS information
models of expressions prove to be useful.
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INTERNATIONAL STANDARD  ©ISO ISO 13584-20:1998(E)
Industrial automation systems and integration —
Parts library —
Part 20:
Logical resource: Logical model of expressions
1 Scope
This part of ISO 13584 specifies:
— an EXPRESS schema for generic expressions;
— an EXPRESS schema for expressions, that models the subset of the allowed expressions in the
EXPRESS language defined in ISO 10303-11 that corresponds to integer, real, Boolean and
string data types. This schema uses the resources defined in the generic expression schema.
The following are within the scope of this part of ISO 13584:
— the exchange of expressions that involve both constants and variables;
— the function that checks whether or not a numeric expression should evaluate to an integer
value;
— the constraints which ensure that an expression is semantically correct;
— the computation of the variables or functions used in an expression;
— the function that checks if an expression may be mapped on to the SQL query language.
The following are outside the scope of this part of ISO 13584:
— the assignment of values to variables within some context;
— the triggering mechanism that computes the value of an expression in a given context.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute
provisions of this part of ISO 13584. For dated references, subsequent amendments to, or revisions
of, any of these publications do not apply. However, parties to agreements based on this part of ISO
13584 are encouraged to investigate the possibility of applying the most recent editions of the
normative documents indicated below. For undated references the latest edition of the normative
document referred to applies. Members of IEC and ISO maintain registers of currently valid
International Standards.
ISO/IEC 9075: 1992, Information technology — Database languages — SQL.
ISO 10303-11: 1994, Industrial automation systems and integration — Product data representation
and exchange — Part 11: Description methods: The EXPRESS language reference manual.
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ISO 13584-20:1998(E)
ISO 10303-44: 1994, Industrial automation systems and integration — Product data representation
and exchange — Part 44: Integrated generic resources: Product structure configuration.
3 Terms and definitions
For the purposes of this part of ISO 13584, the following terms and definitions apply.
3.1 Terms and definitions from ISO 10303-11
For the purposes of this part of ISO 13584, the following terms and definitions given in
ISO 10303-11:1994 (which are repeated below for convenience) apply.
3.1.1
data type
a domain of values.
[ISO 10303-11:1994]
3.1.2
entity
a class of information defined by common properties.
[ISO 10303-11:1994]
3.1.3
entity data type
a representation of an entity. An entity data type establishes a domain of values defined by common
attributes and constraints.
[ISO 10303-11:1994]
3.1.4
entity (data type) instance
a named unit of data which represents a unit of information within the class defined by an entity. It is a
member of the domain established by an entity data type.
[ISO 10303-11:1994]
3.2 Terms and definitions from ISO 10303-44
For the purpose of this part of ISO 13584, the following terms and definitions given in ISO
10303-44:1994 (which are repeated below for convenience) apply.
3.2.1
ancestor node
any node that can be reached from a given node, by suc
...