const nDraw=9, nGoal=(nDraw/2);  // Basic
var [const] UH=Utils.Helpers; // baked in stash of goodies
deck:=Walker.cproduct("red green purple".split(), // Cartesian product of 4 lists of lists
		"one two three".split(),    // T(1,2,3) (ie numbers) also works
		"oval squiggle diamond".split(),
		"solid open striped".split()).walk();
reg draw,sets,N=0;
do{ N+=1;
   draw=deck.shuffle()[0,nDraw]; // one draw per shuffle
   sets=UH.pickNFrom(3,draw)  // 84 sets of 3 cards (each with 4 features)
        .filter(fcn(set){    // list of 12 items (== 3 cards)
                    set[0,4].zip(set[4,4],set[8,4]) // -->4 tuples of 3 features
		    .pump(List,UH.listUnique,"len", // 1,3 (good) or 2 (bad)
		               '==(2))		    // (F,F,F,F)==good
		    .sum(0) == 0 		    // all 4 feature sets good
		 });
}while(sets.len()!=nGoal);

println("Dealt %d cards %d times:".fmt(draw.len(),N));
draw.pump(Void,fcn(card){ println(("%8s "*4).fmt(card.xplode())) });
println("\nContaining:");
sets.pump(Void,fcn(card){ println((("%8s "*4 + "\n")*3).fmt(card.xplode())) });