What are the rules for when to use a colon after the closing
 parenthesis, as in »(a,b): 2«, and when to use a comma, as in
 »(b,c), 2«?

 What are the rules for when to use a space after the character
 after the closing parenthesis, as in »(a,b): 2«, and when to
 use no space there, as in »(c,d,e):3«?

...

...

Replace the ArrayList with a Map, with responses as keys, and the count
of the number of appearances so far of the response as value.

Patricia

 And, adding to my previous two questions:

 Which rule determines the sorting order for tuples
 of the same length?

~~

 The following program is using my GPLd library »ram.jar«
 for the tuple type:

class NumericMapUtils
{ public static <D> void addTo
 ( final java.util.Map<D,java.lang.Integer> map, final D d, final int i )
 { map.put( d, i +( map.containsKey( d )? map.get( d ): 0 )); }}

public class Main
{ static de.dclj.ram.type.tuple.ComparableTuple
 <de.dclj.ram.type.tuple.DefaultComparableTuple>
 tuple( java.lang.Comparable ... args ) { return new
   de.dclj.ram.type.tuple.DefaultComparableTuple( args ); }
   
 public static void main( final java.lang.String[] args )
 { final java.util.Map
   <de.dclj.ram.type.tuple.ComparableTuple,java.lang.Integer> map =
   new java.util.TreeMap
   <de.dclj.ram.type.tuple.ComparableTuple,java.lang.Integer>();
   NumericMapUtils.addTo( map, tuple( 'a', 'b' ), 1 );
   NumericMapUtils.addTo( map, tuple( 'b', 'c' ), 1 );
   NumericMapUtils.addTo( map, tuple( 'a', 'b' ), 1 );
   NumericMapUtils.addTo( map, tuple( 'b', 'c' ), 1 );
   NumericMapUtils.addTo( map, tuple( 'c', 'd', 'e' ), 1 );
   NumericMapUtils.addTo( map, tuple( 'a', 'd', 'e' ), 1 );
   NumericMapUtils.addTo( map, tuple( 'c', 'd', 'e' ), 1 );
   NumericMapUtils.addTo( map, tuple( 'c', 'd', 'e' ), 1 );

   for( final de.dclj.ram.type.tuple.ComparableTuple d : map.keySet() )
   java.lang.System.out.println( d.toString() + map.get( d )); }}

 The output is

( a; b )2
( a; d; e )1
( b; c )2
( c; d; e )3

~~

 Here is a program in Java SE not using my library, and
 a somewhat more specialized »NumericMap« class.
 It also uses another sorting method for the output.

class NumericMap
{ final java.util.Map
 <java.lang.String,java.lang.Integer> map =
 new java.util.TreeMap
 <java.lang.String,java.lang.Integer>();

 public void increment
 ( final char ... a  )
 { final java.lang.String s = a.length + java.util.Arrays.toString(a);
   map.put( s, 1 +( map.containsKey( s )? map.get( s ): 0 )); }

 public void print()
 { for( final java.lang.String d : map.keySet() )
   java.lang.System.out.println( d.toString() + map.get( d )); }}

public class Main
{  
 public static void main( final java.lang.String[] args )
 { NumericMap numericMap = new NumericMap();
   numericMap.increment( 'a', 'b' );
   numericMap.increment( 'b', 'c' );
   numericMap.increment( 'a', 'b' );
   numericMap.increment( 'b', 'c' );
   numericMap.increment( 'c', 'd', 'e' );
   numericMap.increment( 'a', 'd', 'e' );
   numericMap.increment( 'c', 'd', 'e' );
   numericMap.increment( 'c', 'd', 'e' );
   numericMap.print(); }}

 The output is:

2[a, b]2
2[b, c]2
3[a, d, e]1
3[c, d, e]3