This discussion is an attempt to formalize the existing logical structure surrounding the use of the Numeric Indicator according to §7-12 of Rule II. of the Nemeth Code with some amplification from other rules. The rules for numbers in non-decimal bases and for numbers in Tables and Diagrams are not covered here.
The intent is to provide some information that might be a useful start to defining a DTD or some sort of Schema for Nemeth. References in brackets are to the Nemeth Code.
A literary number is as defined in the English Braille Code and is not discussed here.
A Nemeth number used in technical material is based on the Nemeth numerical symbols. These include the Nemeth numeral cells (0-9 in Braille ASCII), the decimal point (. in Braille ASCII), and any embedded mathematical commas (, in Braille ASCII) or spaces used for grouping digits. Note that a mathematical comma used for grouping is never followed by a space; this rule serves to distinguish the mathematical comma used as a numerical symbol from one used as punctuation since it must be followed by a space in the latter context. A number, with or without grouping symbols, is always mathematical context.
[Rule II, §7-8] According to the scheme that I am proposing, a number, per se, could only be a child element of one of the four proposed number elements:
The physical cell dots 3-4-5-6 or Braille ASCII # is genererally called the number sign in literary braille and the Numeric Indicator (NI) in Nemeth. This cell has four semantic forms related to its use with numerals. It is also used as part of the closing fraction indicators as specified in Rule XII.
See elsewhere for the use of the literary numbers.
These are the rules for the use of the four number elements that use Nemeth numbers:
A numerical break or numbreak is one of the following:
A spacing break or spacingbreak [9a] is one of the following:
A literary break or litbreak is one of the following:
The literary punctuation subset is comprised of the following cells:
The special literary punctuation subset is comprised of the cells with the following semantics. These semantic cells are always preceded by a punctuation indicator in a mathematical context to distinguish them from the same physical cells being used as numerals.
The dual-use literary punctuation mark subset is comprised of the dual-use physical symbols when used within or immediately following a literary (non-mathematical) context.
A PNE is used in any context where an ANE or INE is not mandated. [11e] This includes but is not limited to
According to the Nemeth rules, a punctuation mark from the special literary set defined here requires a preceding punctuation indicator in a mathematical context. This will be discussed elsewhere. Punctuation marks that are not in the special literary punctuation subset are treated as follows when used with numerals.
Comma. According to the Nemeth rules, the mathematical comma, which must generally be followed by a space, is used rather than the literary comma immediately following a Nemeth numeral. The mathematical comma is a physically different cell from the literary comma. An NI is not needed immediately following a mathematical comma; the rules for the use of the NI following a space are covered by the rules for a numerical break.
Hyphen, dashes, ellipsis. According to the Nemeth rules, these dual-use punctuation marks are mathematical, rather than literary, punctuation marks when used directly between or immediately following Nemeth numbers (or other mathematical expressions) and thus do not require the use of the CNI to effect a change of semantics. A range would be transcribed as for example, #1-3, whereas a time of day would be transcribed as for example, #2_:#45 where the underscore is the Braille ASCII for the punctuation indicator needed before the colon.
Apostrophe-ess. According to the Nemeth rules, an ordinal ending or a plural or possessive ending, whether or not preceded by an apostrophe (with its required preceding punctuation indicator), that follows a Nemeth number does not effect a change of semantics and is always a mathematical expression. In the unlikely situation of a Nemeth number immediately such a construct, an NI wouldn't be used since this would be neither a literary break nor a numerical break.