
<h2 class="wimscenter">Feedback according to answers</h2>

You may define conditions (on the values of user answers) under which a
message will be printed on the page of results. A common use of this feature
will be to give warnings when a typical error to the exercise is detected.
<p>
An arbitrary number of feedbacks can be added, on any kind of replies
(freestyle or multiple choice). The syntax is as follows.
</p><pre>
\feedback{CONDITION}{MESSAGE}
</pre>
The line can be put into the field of parameters (under guided mode) or
anywhere in the source (under raw mode).
<p>
When <span class="tt">CONDITION</span> is met,
<span class="tt">MESSAGE</span> will be shown to the user in the result page. Values of
user replies can be put into both via the variables <span class="tt wims_code_variable">\reply1</span>,
<span class="tt wims_code_variable">\reply2</span>,... (for freestyle replies), <span class="tt wims_code_variable">\choice1</span>,
<span class="tt wims_code_variable">\choice2</span>,... (for multiple choices). The order in the variables
is the order of their appearance in the source (or in the form under the
guided mode).
</p><p>
<span class="tt">MESSAGE</span> is a free text, accepting embedded html tags and
mathematical symbols.

</p><p>
One can use also the variables <span class="tt wims_code_variable">\sc_reply1</span>, <span class="tt wims_code_variable">\sc_reply2</span>,
... which are equal to  1 in case of good user reply, 0 in case of false
user reply and 0.5 in case of good reply up to numerical precision. This variable
does not take care of conditions and is empty in the case where the
answer is analyzed only with conditions.
</p>
$table_header
<caption>Examples of conditions
<small>
!href target=wims_mhelp cmd=help&special_parm=if complete list
</small>
</caption>
$table_hdtr<th>condition</th><th>when it is met</th></tr>
$table_tr<td class="tt wims_code_words">\reply1=5</td><td>first freestyle reply is exactly equal to 5</td></tr>
$table_tr<td class="tt wims_code_words">\reply1&gt;\reply2+2</td><td>first freestyle reply is &gt; second one plus 2</td></tr>
$table_tr<td class="tt wims_code_words">\choice1=Yes and \choice2=No</td>
  <td>first multiple choice is Yes and second is No (<b>attention</b> the
comparison in multiple choices is case-sensitive!)
</td></tr>
$table_tr<td class="tt wims_code_words">\reply1&lt;5 or \reply1&gt;8</td>
  <td>first reply is outside the range from 5 to 8.
</td></tr>$table_tr<td><tt class="wims_code_words">3 isitemof \reply1
  <td>the first reply, of type "set" or "vector", contains a component "3".
</td></tr>
$table_end
<p>
<b>Known-bug</b>. You should avoid mixing <span class="tt wims_code_variable">\reply</span> and
<span class="tt wims_code_variable">\choice</span> within one same condition. Otherwise the result will be
unpredictable.
</p>
