Combine two Linq predicate expression

ExpressionExtensions.cs

namespace System.Linq.Expressions
{
    public static class ExpressionExtensions
    {
        public static Expression<Func<T,bool>> And<T>(this Expression<Func<T,bool>> left, Expression<Func<T, bool>> right)
        {
            if (left == null) return right;
            var and = Expression.AndAlso(left.Body, right.Body);
            return Expression.Lambda<Func<T, bool>>(and, left.Parameters.Single());
        }

        public static Expression<Func<T, bool>> Or<T>(this Expression<Func<T, bool>> left, Expression<Func<T, bool>> right)
        {
            if (left == null) return right;
            var and = Expression.OrElse(left.Body, right.Body);
            return Expression.Lambda<Func<T, bool>>(and, left.Parameters.Single());
        }
    }
}