How do you punctuate elliptical constructions?

Solution 1:

Source: NASA's Handbook for Technical Writers and Editors

When clauses in a sentence contain repeated elements (for example, the verb), the omission of these elements is indicated by a comma, and a semicolon separates the elliptical clauses.

Wind speed is obtained from antenna brightness temperature; rain rate, from the brightness temperature difference at two frequencies; and wind vector, from radar cross section.

The comma may be omitted if the clauses are short. Of course, when the commas are unnecessary to indicate omission, the semicolon can be replaced by a comma so long as the clauses are joined by a conjunction:

Wind speed is obtained from antenna brightness temperature, and wind vector from radar cross section.

But

Wind speed is obtained from antenna brightness temperature; wind vector, from radar cross section.

Therefore, I think the right choices would be:

Asterix defeated seven Romans; Obelix, three.

Asterix defeated seven Romans, and Obelix three.

Obelix missed her; she, him.

Obelix missed her, and she him.

Solution 2:

A semicolon really helps to separate matters, without making the ideas seem to distant. It's usage is voluntary, but in this case I would recommend it:

Asterix defeated seven Romans; Obelix, three.

If you were to add a conjunction, the first two examples would have been fine, but the comma musn't be missed out.

For the last case presented, I would choose:

Asterix missed her, and she him.

but you could choose "Asterix missed her, and she, him" as well.

Solution 3:

I would recommend for the following as the clearest of each choice.

Asterix defeated seven Romans, Obelix three.

Asterix defeated seven Romans, and Obelix three.

Asterix missed her, and she him.

And of the first two, I would choose this one as the clearest:

Asterix defeated seven Romans, and Obelix three.

However, I suspect much of this is down to style and consistency rather than correctness.