Expand/Clarify/Reword cmp-ok section

doc/Language/testing.pod

@@ -242,20 +242,25 @@ not sorted, and converting a L<Hash|/type/Hash> to a string loses information.
 
 =item X<cmp-ok($value, $comparison, $expected, $description?)|cmp-ok>
 
-Compares C<$value> and C<$expected> with the given C<$comparison> operator and
-passes the test if the comparison yields a C<True> value.  For ease of use,
-operators may be passed as strings, such as C<'=='> or C<'~~'>.  The function
-accepts an optional C<$description> of the test.
+Compares C<$value> and C<$expected> with the given C<$comparison> comparator and
+passes the test if the comparison yields a C<True> value. The C<$description>
+of the test is optional.
+
+The C<$comparison> comparator can be either a L<Callable> or 
+a L<Str> containing a I<core> infix operator, such as C<'=='> or C<'~~'>.
 
     cmp-ok 'my spelling is apperling', '~~', /perl/, "bad speller";
 
-The C<$comparison> can be any L<Callable>, allowing you to use custom comparisons:
+A L<Callable> C<$comparison> lets you use custom comparisons:
+
+    sub my-comp { $^a / $^b  < rand };
+    cmp-ok 1, &my-comp, 2, 'the dice giveth and the dice taketh away'
 
-    cmp-ok 2, sub { $^a.is-prime and $^b.is-prime and $^a < $^b }, 7,
+    cmp-ok 2, -> $a, $b { $a.is-prime and $b.is-prime and $a < $b }, 7,
         'we got primes, one larger than the other!';
 
 B<Note:> user-defined operators cannot be passed as strings. Use
-the C<&[]> notation instead:
+the C<&[]> notation to create a L<Callable> for them instead:
 
     sub infix:<◀> { $^a < $^b };
     cmp-ok 4, &[◀], 5, 'comparing using my fancy operator';