Не удалось привести тип объекта "NHibernate.Hql.Ast.HqlBitwiseAnd" к типу "NHibernate.Hql.Ast.HqlBooleanExpression"

    internal class AndSpecification<TEntity> : ISpecification<TEntity>
    {
        private ISpecification<TEntity> spec1;
        private ISpecification<TEntity> spec2;

        internal AndSpecification(ISpecification<TEntity> s1, ISpecification<TEntity> s2)
        {
            spec1 = s1;
            spec2 = s2;
        }

        public Expression<Func<TEntity, bool>> Predicate
        {
            get 
            {
                return spec1.Predicate.And(spec2.Predicate);
            }
        }
    }

    public static class Utility
    {
        public static Expression<T> Compose<T>(this Expression<T> first, Expression<T> second, Func<Expression, Expression, Expression> merge)
        {
            // build parameter map (from parameters of second to parameters of first)
            var map = first.Parameters.Select((f, i) => new { f, s = second.Parameters[i] }).ToDictionary(p => p.s, p => p.f);

            // replace parameters in the second lambda expression with parameters from the first
            var secondBody = ParameterRebinder.ReplaceParameters(map, second.Body);

            // apply composition of lambda expression bodies to parameters from the first expression 
            return Expression.Lambda<T>(merge(first.Body, secondBody), first.Parameters);
        }

        public static Expression<Func<T, bool>> And<T>(this Expression<Func<T, bool>> first, Expression<Func<T, bool>> second)
        {
            return first.Compose(second, Expression.And);
        }
    }

    public class ParameterRebinder : ExpressionVisitor
    {
        private readonly Dictionary<ParameterExpression, ParameterExpression> map;

        public ParameterRebinder(Dictionary<ParameterExpression, ParameterExpression> map)
        {
            this.map = map ?? new Dictionary<ParameterExpression, ParameterExpression>();
        }

        public static Expression ReplaceParameters(Dictionary<ParameterExpression, ParameterExpression> map, Expression exp)
        {
            return new ParameterRebinder(map).Visit(exp);
        }

        protected override Expression VisitParameter(ParameterExpression p)
        {
            ParameterExpression replacement;

            if (map.TryGetValue(p, out replacement))
                p = replacement;

            return base.VisitParameter(p);
        }
    }

 ISession.Query<T>().Where(AndSpecification<T>.Predicate)

    public class Test
    {
        public virtual int ID { get; set; }
        public virtual string Text { get; set; }
        public virtual int Number { get; set; }
    }

Expression<Func<Test, bool>> predicate1 = x => x.Text.Length > 5 && x.Number > 0;

.Lambda #Lambda1<System.Func`2[NHLinqTest.Test,System.Boolean]>(NHLinqTest.Test $x) {
    ($x.Text).Length > 5 && $x.Number > 0
}

 var y = Expression.Parameter(typeof(Test));

            var predicate2 = Expression.And(
                Expression.GreaterThan(
                    Expression.Property(Expression.Property(y, "Text"), "Length"),
                    Expression.Constant(5)),
            Expression.GreaterThan(
                Expression.Property(y, "Number"),
                    Expression.Constant(0)));

($var1.Text).Length > 5 & $var1.Number > 0