An ultrafilter is maximal in the sense that if any other element of the poset not already in it were added to it, one could deduce (from the laws which define the filter, and the given ordering relation, i.e., the structure of the poset) that the resulting filter must be improper; i.e., it must contain all the elements of the poset.

Quare Opium facit dormire: ... Quia est in eo Virtus dormitiva. (Why Opium produces sleep: ... Because there is in it a dormitive power.)

17: The three major forms of Modern English—British, American, and Commonwealth—are very nearly identical on the printed page, a great source of the linguistic unity and cultural solidarity of the Anglo-Saxon civilization. 25: Commonwealth English is very young in the prestige of its independent status.

The note strikes the young artist curiously, but just then the squeaky elevator arrives with a sorrowsome ding and she is distracted by its squawking doors and a grumbling old lady with a shopping bag.