List<Expression> exptree = new List<Expression>();
var resultEXpression = exptree.Skip(1).Aggregate(exptree.FirstOrDefault(),
(exp1,exp2) => Expression.And(exp1,exp2));
List<Expression> exptree = new List<Expression>();
var resultEXpression = exptree.Skip(1).Aggregate(exptree.FirstOrDefault(),
(exp1,exp2) => Expression.And(exp1,exp2));