testimony came at the trial of Carlos Eduardo Restrepo, who is accused of laundering more than $10 million for the Medellin cartel through a currency-exchange company in Greenwich that was an undercover ''sting'' operation set up by the Federal Bureau of Investigation. Money laundering, under a 1986 Federal law, is the concealment and illegal transfer of money obtained through unlawful acts.The United States Attorney in Connecticut, Stanley A. Twardy Jr., said in an interview that Mr. Restrepo is the first person to be tried under the Federal law. Mr. Restrepo, who is 38 and who has described himself as a businessman, has pleaded not guilty.