SOMOZA YIELDSPOST AND ARRIVES IN U.S.; FIGHTING CONTINUES
Gen Anastasio Somoza Debayle resigns as President of Nicaragua; flies into exile in Miami, Fla; fighting continues; joint session of Nicaragua's Congress accepts Somoza's resignation and names Chamber of Deputies President Francisco Urcuyo Malianos to succeed him; Urcuyo appears intent on withholding power from rebel junta; urges guerrillas to lay down their arms and calls for talks among all democratic groups, nationwide address; Amb Lawrence A Pezzullo, after meeting with Urcuyo, reportedly tells opposition leaders that there has been 'violation' of agreement that was worked out with Somoza and that US can play no further role in negotiations; portrait of Somoza as he arrives in Miami and of Augusto Cesar Sandino, foe of late President Somoza Garcia; illus of Sandinist guerrillas celebrating Somoza's resignation (L)