What's the opposite of "precede"?

Line B is preceded by Line A.

Line A is followed by Line B.

EDIT after the first comment:

To make it active, you can try:

Line B follows Line A.

Alternatively, you could say:

Line B comes after Line A.

The most natural-sounding way you could say it (other than using "follows") is probably: "is next after".

If "line A" precedes "line B", "line B" is/comes next after "line A".

"Succeed" is the technical antonym to "precede", but "line B succeeds line A" does not sound as natural.

Then again, though you discarded the term "follows", it may turn out to be a good choice.

Antecede is synonymous with precede (http://www.merriam-webster.com/dictionary/antecede). I believe the proper "mirror word" to precede is succeed. This usage is most commonly seen in the form predecessor/successor, but it's perfectly valid to say that line a precedes line b and line b succeeds line a.