Method Equals

Gives true when the given object is an either of this same type which is equal to this one.

public override bool Equals(object? obj)

bool: true if obj is an either of the same type which operator ==(Either<T1, T2, T3, T4>, Either<T1, T2, T3, T4>) considers equal to this one.

An either is never equal to the bare value it holds, only to a second either.

Gives true when the given instance is equal to this one.

public bool Equals(Either<T1, T2, T3, T4> other)

bool: true if operator ==(Either<T1, T2, T3, T4>, Either<T1, T2, T3, T4>) considers the two equal.

The same compare as operator ==(Either<T1, T2, T3, T4>, Either<T1, T2, T3, T4>), with the name that Default looks for. Thus, a compare of these in a collection does not box the two operands, as Equals(object?) must.