get_ng1 :: [Literal] -> CClause
get_ng1 b =
  let pb = [ a | PAtom a <- b ]
      nb = [ a | NAtom a <- b ]
  in
  ((atoms2vars pb), ((BLit b):(atoms2vars nb)))
get_ng1 :: [Literal] -> CClause
get_ng1 b =
  let pb = [ a | PAtom a <- b ]
      nb = [ a | NAtom a <- b ]
  in
  ((atoms2vars pb), ((BLit b):(atoms2vars nb)))
get_ng1 b =
  let pb = [ a | PAtom a <- b ]
      nb = [ a | NAtom a <- b ]
  in
  ((atoms2vars pb), ((BLit b):(atoms2vars nb)))