"to communicate (with)," 1590s; earlier "to move about, live, dwell" (mid-14c.), from Old French converser "to talk" (12c.), from Latin conversari (see conversation). Related: Conversed; conversing.
"exact opposite," 1560s, from Latin conversus "turn around," past participle of convertere "to turn about" (see convert). Originally mathematical. The noun is attested from 1550s in mathematics. Related: Conversely.
logic
The truth of a proposition of the form A => B and its converse B => A are shown in the following truth table:
A B | A => B B => A ------+---------------- f f | t t f t | t f t f | f t t t | t t
(2002-07-12)
in logic, the proposition resulting from an interchange of subject and predicate with each other. Thus, the converse of "No man is a pencil" is "No pencil is a man." In traditional syllogistics, generally only E (universal negative) and I (particular affirmative) propositions yield a valid converse. The converse of a relation R is the relation S such that xSy (y has the relation S to x) if, and only if, yRx (x has the relation R to y). If a relation is identical to its converse, it is symmetric