public Or(AbstractExpression left, AbstractExpression right) : base(left, right)
 {
 }
 public Not(AbstractExpression expr) : base(expr)
 {
 }
 //TODO naprawić to
 public BinaryExpression(AbstractExpression left, AbstractExpression right)
 {
     this.left  = left;
     this.right = right;
 }
 public UnaryExpression(AbstractExpression expr)
 {
     this.expr = expr;
 }