You may be surprised to learn that “The Liar,” which just opened off-Broadway at Classic Stage Company, is not a new play about a particular political leader whose administration has lately been proposing so-called “alternative facts.”

Rather, “The Liar” is a 17th-century French farce by Pierre Corneille (who is best-remembered for tragedies where honor takes precedence over life and love), which here has been translated and adapted by David Ives (“Venus in Fur,” numerous one-act comedies).

Not unlike Shakespeare’s “The Comedy of Errors,” “The Liar” is a boy-meets-girl comedy in which a simple mistake of identity leads to escalating confusion, deception and chaos until the inevitable happy ending arrives. The text, which is made up of rhymed couplets, combines sly wit and old-fashioned romantic rituals with course humor, a modern point of view and countless anachronisms.

Dorante (Christian Conn), a law school graduate newly arrived in Paris, can’t help but spontaneously construct head-spinning “alternative facts” about his past accomplishments and love life.

His father (Adam LeFevre) has arranged for Dorante to marry a local girl (Ismenia Mendes) that Dorante is in fact already wooing. But because Dorante mixed up the girl’s name during their initial encounter, he does everything in his power to prevent the marriage.

Dorante’s levelheaded manservant (Carson Elrod) spends much of the play puzzled by and commenting on his master’s bad habits. And did I mention the identical twins (both played by Kelly Hutchinson) who work as maids for different characters?

Staged with speedy comedic flow by Michael Kahn (artistic director of the prestigious Shakespeare Theatre Company in Washington, D.C.), “The Liar” is a lighthearted, light as a feather delight. The small cast, wearing deluxe period attire, delivers the rhymed banter and physical gags (such as repeated slapping and mimed swordplay) with youthful, hyperactive vigor.