Add official position on example ranges to style.md

[chbrown]

What to do with example ranges? Options:

Format	Comment
(1)--(2)	n-dash conflicts with \dash ultimatum
(1) -- (2)	precedent of page range does not have surrounding space
(1)-(2)
(1-2)	might conflict with systems that might label a single example as (1-2) or with built-in \ref
(1) to (2)	verbose
(1) through (2)	verbose

Corollary: what about sub-examples?

Format	Comment
(1a)--(1c)
(1a--c)	might not play nice with built-in \ref
(1a-c)	ditto
(1b)--(4b)	not unheard of!

[fintelkai]

Definitely, (1)--(2), on the model of page ranges and other numerical ranges. The \dash edict is about anything that should be an em-dash: parenthetical remarks.

[fintelkai]

I'm vacillating between (1a--c) and (1a-c). And when the main number is different, definitely (1b)--(4b).