LinqAlias by RyotaMurohoshi

<PackageReference Include="LinqAlias" Version="0.0.2.1" />

.NET API 5,120 bytes

 EnumerableAlias

public static class EnumerableAlias
public static bool Exists<TSource>(this IEnumerable<TSource> source, Func<TSource, bool> selector)

public static IEnumerable<TSource> Filter<TSource>(this IEnumerable<TSource> source, Func<TSource, bool> predicate)

public static IEnumerable<TResult> FlatMap<TSource, TResult>(this IEnumerable<TSource> source, Func<TSource, IEnumerable<TResult>> selector)

public static TAccumulate Fold<TSource, TAccumulate>(this IEnumerable<TSource> source, TAccumulate seed, Func<TAccumulate, TSource, TAccumulate> func)

public static bool ForAll<TSource>(this IEnumerable<TSource> source, Func<TSource, bool> predicate)

public static IEnumerable<TResult> Map<TSource, TResult>(this IEnumerable<TSource> source, Func<TSource, TResult> selector)

public static TSource Reduce<TSource>(this IEnumerable<TSource> source, Func<TSource, TSource, TSource> func)