As assistant U.S. Attroney Henry F. Schuelke described it, one simple equation explained all the complex transactions: Joseph P. Yeldell used his position in the District government to help Dominic F. Antonelli make money, and Antonelli reciprocated by helping Yeldell obtain badly needed loans.

"Each and every one of these steps is possible only because they had an agreement," Schuelke told the jury in his opening statement, describing what he said were the financial arrangements that led to the bribery and conspiracy indictments of Yeldell and Antonelli in April 1978.

But as defense attorney Edward Bennett Williams traced the loans that Antonelli helped Yeldell obtain and the history of a multi-million-dollar lease that the District government took on an Antonelli-controlled property, he maintained there was no connection between the two events.

"We will show you," Williams told the panel in his opening statement, "there was no conspiracy between Mr. Antonelli and Mr. Yeldell to defraud anyone.We will show you no one was defrauded.

"We will show you there was no bribe paid, and we will show you there was no bribe received. We will show you there was nothing corrupt, deceitful, underhanded or sinister in all the dealings involving Antonelli and Yeldell," he said.

It took about three hours for both sides in this trial to finish their low-key descriptions of what the pile of documents in the courtroom means. Then, with a nod from U.S. District Judge Gerhard A. Gessell, who came here from Washington to preside, the prosecutors started to call the witnesses who will chronicle how the case evolved.

The uncontested testimony of the first prosecution witnesses was designed to show that by 1975, a travel agency formed by Yeldell and a group of black businessmen was in debt and floundering with $73,000 in outstanding loans and with their sources of credit drying up.

Then Antonelli's business partner, John W. Lyon, took the witness stand and, responding coldly to prosecutors' questions, described how Yeldell "came to see me" to ask his help in obtaining a loan to help meet interest payments on the debts of Entrepreneur Travel Associates Inc.

"I set up an appointment in Mr. Antonelli's office sometime thereafter," Lyon said. After a meeting in December 1973, Antonelli and Lyon agreed to co-sign a bank loan to Yeldell, guaranteeing that they would repay the money if Yeldell did not, Lyon testified.

Asked if they examined the financial statements of the travel agency before agreeing to guarantee the loan, Lyon answered that "we weren't making the loan on the basis of the financial shape they were in; we were trying to help somebody."

That $11,000 loan was the first of a series of short-term loans totaling $21,500 which Antonelli assisted Yeldell in obtaining from the Madison National Bank, an institution which Antonelli had helped to found and in which he is a major stockholder, according to Karl Donald Menefee, chairman of the board of Madison National Bank, who followed Lyon on the witness stand.

These loans, which were refinanced at least eight times, were the precursors of a secret $33,000 loan that Antonelli made to Yeldell through a fictitious person, or "straw," in 1976, the government alleges.

The final loan, prosecutors say, effectively was a payoff to Yeldell for his work in circumventing a variety of government regulations and other obstacles to allow the D.C. Department of Human Resources, which he headed at the time, to take out a 20 year, $5.6 million lease on Antonelli's building at 60 Florida Ave. NE in Washington.