Final answer:
Cyrano de Bergerac insults Valvert by composing a clever poem during a sword fight, mockingly highlighting Valvert's lack of wit.
Step-by-step explanation:
You are referring to a different play than where Cyrano de Bergerac insults the character Valvert. The text you've provided doesn't appear to be related to that scenario. In Edmond Rostand's play Cyrano de Bergerac, Cyrano is known for his quick wit and mastery of language, which he demonstrates in his verbal duel with the character Valvert.
In one of the most famous scenes, Cyrano insults Valvert by composing a poem as he engages in a sword fight, mocking Valvert's lack of wit and creativity. Cyrano's ability to craft such an eloquent series of insults while simultaneously dueling showcases both his physical and intellectual prowess.