" for certain pairs of elements in the set, one of the elements precedes the other."
Yeah this and this
" In words, when�a�≤�b, one may say that�b�covers�a�or that�b�precedes�a, or that�b�reduces�to�a."
If that's what you mean, if not you lost me.

Youth lives by personality, age lives by calculation. -- Aristotle on a calendar