PRAGUE AIDES SAY GERMAN RED UNITS LEFT BY THIRD DAY; Pullout Is Linked to Russians' Second Thoughts on Role in the Occupation TWO DIVISIONS INVOLVED Moscow's Concern About Violating Potsdam Pact Is Viewed as Factor Prague Aides Say Two East German Divisions Left Within Three Days
(includes sec X); Soviet troops remain at TV-radio stations although most Soviet troops in Prague are not visible