DATE: 1999-10-27

 

L2/99-346

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

1999-10-27

5. Requesters 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

25

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 plus a few symbols

6b. Font currently available?

Microsoft Symbol font plus some glyphs from M. Everson

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, Frank da Cruz

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

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

(plus a few others given in the list below) appear in a number of existing character encodings. These encodings include TeX, PostScript, the Hewlett Packard Math8 character set, the Microsoft Symbol font, and DEC VT series terminals, clones and various emulation programs. They are used by technical word processing software to display arbitrarily large versions of (, ), [, ], {, }, , and . 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 (when the symbol exists in the PostScript symbol encoding vector, the PostScript name is also given; else the name from some other standard is given):

 

LEFT PARENTHESIS UPPER HOOK

PostScript parenlefttp

LEFT PARENTHESIS EXTENSION

PostScript parenleftex

007C | VERTICAL BAR

2758 | LIGHT VERTICAL BAR

CURLY BRACE EXTENSION

RIGHT BRACKET EXTENSION

RIGHT CURLY BRACE EXTENSION

LEFT BRACKET EXTENSION

LEFT CURLY BRACE EXTENSION

INTEGRAL EXTENSION

LEFT PARENTHESIS LOWER HOOK

PostScript parenleftbt

RIGHT PARENTHESIS UPPER HOOK

PostScript parenrighttp

RIGHT PARENTHESIS EXTENSION

PostScript parenrightex

RIGHT PARENTHESIS LOWER HOOK

PostScript parenrightbt

LEFT BRACKET UPPER CORNER

PostScript bracketlefttp

LEFT BRACKET EXTENSION

PostScript bracketleftex

LEFT BRACKET LOWER CORNER

PostScript bracketleftbt

RIGHT BRACKET UPPER CORNER

PostScript bracketrighttp

RIGHT BRACKET EXTENSION

PostScript bracketrightex

RIGHT BRACKET LOWER CORNER

PostScript bracketrightbt

LEFT CURLY BRACE UPPER HOOK

PostScript bracelefttp

LEFT CURLY BRACE MIDDLE PIECE

PostScript braceleftmid

LEFT CURLY BRACE LOWER HOOK

PostScript braceleftbt

CURLY BRACE EXTENSION

PostScript braceex (used for left and right)

RIGHT CURLY BRACE UPPER HOOK

PostScript bracerighttp

RIGHT CURLY BRACE MIDDLE PIECE

PostScript bracerightmid

RIGHT CURLY BRACE LOWER HOOK

PostScript bracerightbt

INTEGRAL EXTENSION

PostScript integralex

HORIZONTAL LINE EXTENSION

PostScript arrowhorizex

UPPER-LEFT OR LOWER-RIGHT BRACE SECTION

IBM SS250000

UPPER-RIGHT OR LOWERLEFT BRACE SECTION

IBM SS240000

SUMMATION SYMBOL TOP

DEC Tech 03/01, DG Math 01/08(2)

SUMMATION SYMBOL BOTTOM

DEC Tech 03/02, DG Math 01/09(2)

 

Differently aligned vertical bars are needed to ensure that the built up symbols fit together correctly and all are in one or more existing standards.