fixes #973 (#1045)

Author: martin-henz

xml/chapter1/section2/subsection6.xml

@@ -657,12 +657,13 @@ function timed_prime_test(n) {
 function start_prime_test(n, start_time) {
     return is_prime(n)
            ? report_prime(get_time() - start_time)
-           : true;
+           : false;
 }
 <SHORT_SPACE_AND_ALLOW_BREAK/>
 function report_prime(elapsed_time) {
     display(" *** ");
     display(elapsed_time);
+    return true;
 }
       </JAVASCRIPT>
     </SNIPPET>
@@ -726,8 +727,8 @@ function search_for_primes(start, times) {
            ? true
            : start &gt; 2 &amp;&amp; start % 2 === 0
            ? search_for_primes(start + 1, times)
-           // if we get undefined -&gt; its a prime
-           : is_undefined(timed_prime_test(start)) 
+           // if we get true, it's a prime
+           : timed_prime_test(start)
            ? search_for_primes(start + 2, times - 1)
            : search_for_primes(start + 2, times);
 }
@@ -740,8 +741,8 @@ function search_for_primes(start, times) {
       <REQUIRES>search_for_primes_definition</REQUIRES>
       <JAVASCRIPT>
 search_for_primes(10000, 3);
-// search_for_primes(100000, 3);
-// search_for_primes(1000000, 3);
+// search_for_primes(10000000, 3);
+// search_for_primes(10000000000, 3);
       </JAVASCRIPT>
       <SCHEME>
       </SCHEME>