import java.util.Scanner;


public class Ex4 {

    /**
     * @param args
     */
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        boolean a, b, c, d, expression;
        a = false;
        b = false;
        c = false;
        d = false;

        System.out.println("L'expression est vraie quand : ");

        do {
            a = !a;
            do {
                b = !b;
                do {
                    c = !c;
                    do {
                        d = !d;
                        expression = (a && b) ^ ! (c && !d);
                        if(expression) {
                            System.out.println("a = "+ (a ? "true" : "false") + ", b = " + (b ? "true" : "false") + ", c = " + (c ? "true" : "false") + ", d = "+(d?"true":"false"));
                        }
                    } while(d);
                } while(c);
            } while(b);
        } while(a);

    }

}