 reserve I for non empty set;
 reserve i for Element of I;
 reserve F for Group-Family of I;
 reserve G for Group;
reserve S for Subgroup-Family of F;

theorem
  for I being empty set
  for F being multMagma-Family of I
  holds product F is trivial Group
proof
  let I be empty set;
  let F be multMagma-Family of I;
  product (Carrier F) = {{}} by CARD_3:10;
  then ex G being strict trivial Group st (product F)=G
  by LmTriv, GROUP_7:def 2;
  hence thesis;
end;
