# Common typesetting issues and Editorial recommendations

## Hyphen vs. Dash

When a concept is named after the names of two or more people, then the correct way to indicate this is with DASH:

• Pell–Lucas numbers
• Cauchy–Bunyakovsky–Schwarz inequality

When a concept is named after the name of one person with a double-barrelled surname, then the correct way to indicate this is with HYPHEN:

• Mittag-Leffler function
• Morgan-Voyce polynomials

When a concept contains a parameter in the name, the correct way to indicate it is with HYPHEN and ITALICS on the parameter:

• k-Pell numbers
• k-Pell–Lucas numbers

## Decimal separator vs. Thousands separator

Being an international journal, and to avoid confusions, NNTDM follows international conventions and standards. The SI metric advises the following:

• Thousands separator is NON-BREAKABLE SPACE (not point or comma).
• In Latex, use the symbol ~ ,
• In MS Word, use the key combination: Ctrl+Shift+Space  .
• Decimal separator is POINT (not comma).

## Bottom line vs. Midline horizontal ellipsis

Mathematical texts often contain bottom line and midline horizontal ellipses, more widely known for the Latex users as \ldots and \cdots , respectively, or the Unicode symbols in Word and .

The distinction between them is subtle: \ldots aligns the ellipsis with the bottom of the text while \cdots centers the ellipsis. Typographical style considerations dictate which of the two commands to use:

• For lists, use \ldots (…) . Example:
• For matrices and binary operations, use \cdots (⋯) . Example:

In addition, matrices further may require the use of a vertical ellipsis and a diagonal (downward-sloped, down-right) ellipsis, denoted respectively by \vdots (⋮) and \ddots (⋱) .