Clarify the use of decimal commas and thousand separators

[samimaattaCelia]

In Finnish we use decimal commas and whitespace as a thousand separator, which has to be clarified.

Naturally the supplier should use the characters that appear in the book if not specified otherwise, but this might have to be clarified every time a book is ordered, since the supplier might not know what to do in all cases.

Decimal comma in decimal numbers

Use a decimal comma , in decimal numbers (as per MathML Core 3.2.3). The decimal comma is not an operator.

Before there was some confusion if the comma should be treated as an operator - maybe because in the MathML Core 3.2.4 Operator, Fence, Separator or Accent section a comma is described as a separator, but it's alongside a semicolon. They are used as separators (and as operators in MathML sense) when describing points on a plane or in space, but it's not about numbers.

In a number: <mn>2,718281828459045</mn>. Renders as 2,718281828459045. In a point:

<mo>(</mo>
<mi>x</mi>
<mo>,</mo>
<mi>y</mi>
<mo>)</mo>

Renders as (x,y).

Whitespace as thousand separators

A non-breaking space should be used in the thousand separators' place:  . The thousand separator is not an operator. Example: <mn>1&nbsp;000&nbsp;000</mn>, so it renders like so: 1 000 000.

[samimaattaCelia]

Should we include the use of regular whitespace as a thousand separator <mn>1 000 000</mn>? I don't know if that's a problem.