Complex sentence: SNHL came in the 1977--78 season but in the preliminary round they lost series 2--4 against TJ Gottwaldov thus Zvolen never played in the Czechoslovak Extraliga, top level of Czechoslovak hockey.
Split into simpler sentences: SNHL came in the 1977--78 season, but in the preliminary round they lost a series 2--4 against TJ Gottwaldov. Thus Zvolen never played in the Czechoslovak Extraliga, top level of Czechoslovak hockey.