Shortly after yesterday's meeting in La Palma between the two sides in El Salvador's civil war, the members of the guerrilla delegation invited several foreign reporters and independent observers to return with them to their mountain hideout a few miles away.

There, the guerrilla leaders made clear in a wide-ranging interview their continuing doubts about the rule of President Jose Napoleon Duarte and their determination to pursue their military goals. "It's ridiculous to think that the people would lay down their arms," said one.

A transcript of the interview, the most extensive with the guerrilla leadership in recent memory, was made available today by Tommie Sue Montgomery, a professor of political science at Dickinson College.

Each of the four delegates represented one of the five groups that make up the Farabundo Marti National Liberation Front. They were Ferman Cienfuegos, head of the National Resistance; Facundo Guardado Guardado, of the Popular Liberation Forces; Lidia Diaz, of the Central American Revolutionary Workers' Party, and a man identified only as "Comandante Lucio," presumably representing the People's Revolutionary Army. There is some speculation that he is actually a former high-ranking officer of the Salvadoran Army, Francisco Mena Sandoval, whom he strongly resembles. There was no delegate present for the Salvadoran Communist Party, which is the fifth member of the guerrilla coalition.

The group reached guerrilla headquarters after a muddy uphill climb made more difficult by heavy rainfall. While the reporters traveled in a guerrilla-driven truck at first, they slogged the last few hundred yards on foot.

The guerrillas termed the meeting in La Palma "very positive," but their detailed explanation of what they expect from the peace talks and how they view the Duarte government makes clear that any further progress will require hard bargaining.

"It is not just a question of wanting to" make quick progress in the search for peace Cienfuegos said. "We see this as a complicated process, full of nooks and crannies. The peace plan proposed by Duarte must be studied. We have not discussed it among ourselves yet. We have received it and now we must study it."

Duarte's document states that the guerrillas must lay down their arms and join the "democratic political process." But Cienfuegos emphasized that the left has no plans to stop fighting. "One would have to ask the people if they want to put down their arms," he said. "They would answer that it is hard to disarm after 50,000 have been killed. Everything we have achieved to date is a conquest made by our people in arms . . . these weapons have been conquered with the effort of thousands of lives. It's ridiculous to think that our people are going to lay down arms."

Guardado initially shunted aside a question on whether Duarte is really in charge of the military. "That's not a subject for this press conference," he said uncomfortably, but then dove into the topic.

"Duarte affirms that he is commander in chief of the armed forces and that he exercises political power," Guardado said. "We of course cannot confirm that. At this moment the Army is still a decisive force in this country and power is still divided" between the presidency and the military.

Cienfuegos and Guardado were the chief spokesmen at the La Palma meeting. In 1978, Guardado was leader of a radical coalition of urban and rural poor and was perhaps the left's single most charismatic spokesman. Shortly after his arrest and subsequent release in 1978 he went underground.

"The most important thing about this meeting . . . is that for the first time the government has recognized the rebel front as a representative force," Guardado said. "There is no central power in this country. There are two powers, two armies and two important forces. The government does not exercise central power, and it does not represent all the people."

The rebels stressed their belief that the encounter had done much to give them legitimacy both in and out of the country.

They appeared alongside Duarte as peace makers, they said and obtained guarantees that the "peace dialogue" would continue by obtaining an agreement from Duarte to meet a second time.

"We did not bring anything in writing," Cienfuegos said. "Our only concrete proposals were to form a peace commission," which coincided with what the government wanted, and to schedule another meeting.

Using a method they have perfected during the long and difficult process of achieving unity among themselves, the rebels said they kept their aims simple and concrete, and presented only those points on which they thought both sides could agree.