twh270

import java.util.function.*;

/*
 Problem solved -- thanks to https://www.reddit.com/user/Yggval for identifying the trouble
 (see https://www.reddit.com/r/javahelp/comments/gkid8w/trouble_with_generics/)
 
 Working solution follows: essentially, Sequence<T> needs to be Sequence<T, U> so the
 Compose<IdentifierNode, IdentifierNode, TypeExpressionNode> which extends NodeParseRule<IdentifierNode, TypeExpressionNode>
 can map to the first argument of the Sequence constructor.
*/

twh270

import java.util.Scanner;

public class CardFlip {
	static boolean DEBUG = false;

	private enum CardValue {
		A, B, C, D;
	}

	private static class Card {