.cs

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Threading.Tasks;

namespace FunctionalExperimentation.SimpleRefactorings.Medium1.ExtensionsDecorator
{

    public record struct Item(int Id, string Name);

    public static partial class FuntionalExtensions
    {
        public static Func<Item, bool> AsName(this string @name) =>
            item => item.Name == @name;
        public static Func<Item, bool> AsId(this int @id) =>
            item => item.Id == @id;
        public static Func<T, bool> And<T>(this Func<T, bool> @this, Func<T, bool> filter1) =>
            item => @this(item) && filter1(item);
        public static Func<Func<T, bool>, Func<T, bool>> And<T>(this Func<T, bool> @this) =>
            filter1 => item => @this(item) && filter1(item);
        public static Func<Item, bool> AsId(this (Func<Item, bool>, int) @this) => 
            @this.Item1.And(@this.Item2.AsId());
        public static (Func<Item, bool>, int) And(this Func<Item, bool> @this, int x) =>
            (@this, x);
    }


    public class Example
    {
        public static async Task RunAsync()
        {
            List<Item> items = new List<Item> { new Item(1, "a"), new Item(2, "b") };
            //IOperationManager<int, string> operationManager = new OperationManager<int, string>().AddLogger();
            var filtered0 = items.Where("a".AsName());

            var filtered1 = items.Where("a".AsName().And(1.AsId()));
            var filtered2 = items.Where("a".AsName().And()(1.AsId()).And()(_ => true));
            var filtered3 = items.Where("a".AsName().And(1).AsId());
        }
    }
}