DATE: 1999-02-09

 

L2/99-043

DOC TYPE:

Expert contribution

TITLE:

Mathematical brace pieces

SOURCE:

Murray Sargent III

PROJECT:

 

STATUS:

Proposal

ACTION ID:

FYI

DUE DATE:

--

DISTRIBUTION:

Worldwide

MEDIUM:

Paper and html

NO. OF PAGES:

4

A. Administrative

1. Title

Mathematical brace pieces

2. Requester's name

Murray Sargent III

3. Requester type

Expert request.

4. Submission date

1998-12-01

5. Requester’s reference

Scientific and Technical Information Exchange (STIX)

6a. Completion

Complete proposal

6b. More information to be provided?

If requested

 

B. Technical -- General

1a. New script? Name?

No.

1b. Addition of characters to existing block? Name?

Miscellaneous technical

2. Number of characters

18

3. Proposed category

 

4. Proposed level of implementation and rationale

Level 3; requires simple 2D display

5a. Character names included in proposal?

Yes.

5b. Character names in accordance with guidelines?

Yes.

5c. Character shapes reviewable?

 

6a. Who will provide computerized font?

Microsoft Symbol font

6b. Font currently available?

Microsoft Symbol font

6c. Font format?

TrueType

7a. Are references (to other character sets, dictionaries, descriptive texts, etc.) provided?

Yes.

7b. Are published examples (such as samples from newspapers, magazines, or other sources) of use of proposed characters attached?

No

8. Does the proposal address other aspects of character data processing?

No

 

C. Technical -- Justification

1. Contact with the user community?

Yes. Barbara Beeton, Murray Sargent III, Don Carroll

2. Information on the user community?

Mathematical software

3a. The context of use for the proposed characters?

Used in publication of research mathematics and other hard sciences.

3b. Reference

 

4a. Proposed characters in current use?

Yes.

4b. Where?

Worldwide, by scientific and technical publishers, technical word processing programs

5a. Characters should be encoded entirely in BMP?

Yes.

5b. Rationale

Accurate publication of mathematical and scientific research on the Web is impossible without a comprehensive and accurate collection of symbols including various alphabetic variants in common use. Allocation in the BMP is in accordance with the Roadmap.

6. Should characters be kept in a continuous range?

Yes

7a. Can the characters be considered a presentation form of an existing character or character sequence?

No.

7b. Where?

 

7c. Reference

 

8a. Can any of the characters be considered to be similar (in appearance or function) to an existing character?

Yes

8b. Where?

The characters are used to create large forms of existing brackets, braces, parentheses, and integrals

8c. Reference

 

9a. Combining characters or use of composite sequences included?

Yes

9b. List of composite sequences and their corresponding glyph images provided?

na

10. Characters with any special properties such as control function, etc. included?

No

 

D. SC2/WG2 Administrative

To be completed by SC2/WG2

1. Relevant SC 2/WG 2 document numbers:

 

2. Status (list of meeting number and corresponding action or disposition)

 

3. Additional contact to user communities, liaison organizations etc.

 

4. Assigned category and assigned priority/time frame

 

Other Comments

 

The brace, bracket, parenthesis, and integral character pieces shown in the following table

 

æ

ç

è

ö

÷

ø

 

é

ê

ë

 

ù

ú

û

 

ó

ô

õ

 

ì

í

î

ï

ü

ý

þ

ï

 

 

 

 

appear in a number of legacy character encodings. These encodings include TeX, PostScript, the Hewlett Packard Math8 character set, and the Microsoft Symbol font. They are used by technical word processing software to display arbitrarily large versions of (, ), [, ], {, }, and ò. Currently HP printers encode a set of such characters in the private-use zone. The top and bottom portions of the integral sign are already encoded at U+2320 and U+2321, respectively, since they occur in the DOS codepage 850. To be compatible with existing code sets and to aid in the printing and display of 2D mathematics, I propose that the following set of such characters be encoded:

æ LEFT PARENTHESIS UPPER HOOK

ç LEFT ALIGNED VERTICAL BAR

® 007C | VERTICAL BAR

® 2758 | LIGHT VERTICAL BAR

® ï CENTER ALIGNED VERTICAL BAR

® ÷ RIGHT ALIGNED VERTICAL BAR

® ôINTEGRAL VERTICAL BAR

è LEFT PARENTHESIS LOWER HOOK

ö RIGHT PARENTHESIS UPPER HOOK

÷ RIGHT ALIGNED VERTICAL BAR

ø RIGHT PARENTHESIS LOWER HOOK

é LEFT SQUARE BRACKET UPPER CORNER

ë LEFT SQUARE BRACKET LOWER CORNER

ù RIGHT SQUARE BRACKET UPPER CORNER

û RIGHT SQUARE BRACKET LOWER CORNER

ô INTEGRAL VERTICAL BAR

ì LEFT CURLY BRACKET UPPER HOOK

í LEFT CURLY BRACKET MIDDLE PIECE

î LEFT CURLY BRACKET LOWER HOOK

ï CENTER ALIGNED VERTICAL BAR

ü RIGHT CURLY BRACKET UPPER HOOK

ý RIGHT CURLY BRACKET MIDDLE PIECE

þ RIGHT CURLY BRACKET LOWER HOOK

Differently aligned vertical bars are needed to ensure that the built up symbols fit together correctly.