premise: A leader of the Islamic Resistance Movement (Hamas) in Gaza said on Thursday that there was a slight progress made on the issue of free the Israeli soldier held by Palestinian militant groups, adding that more talks were still needed.
  Osama al-Muzini here said that the "Israeli occupation is softening stance gradually," however, "there were many points need to be agreed upon."
  Meanwhile, al-Muzini revealed that Israel has accepted the principle of prisoners-exchange which had been rejected at the beginning.
  He explained that Israel refuses the coincidence principle, saying that "Until recently, Israel used to demand unconditional release of Corporal Gilad Shalit, but now it had agreed to release
  Palestinian prisoners in exchange of him."
  
  Corporal Gilad Shalit was captured by three militant groups, led by Hamas, in a cross-border raid last June. The captors demand to swap him for a number of Palestinian prisoners held in Israel.
   What does "release" refer to?
hypothesis: The captors demand to swap him for a number of Palestinian prisoners