fixes #837

xml/chapter3/section3/subsection5.xml

@@ -1561,6 +1561,53 @@ const answer = v_prod(v_sum("a", "b"), v_sum("c", "d"));
  expression-oriented style in terms of the imperative implementation,
  it is very difficult to do the converse.</FOOTNOTE>
  <LABEL NAME="ex:3_37"/>
+ <SOLUTION>
+ <SNIPPET>
+<REQUIRES>make_connector</REQUIRES>
+<REQUIRES>has_value</REQUIRES>
+<REQUIRES>for_each_except</REQUIRES>
+<REQUIRES>inform_about_value</REQUIRES>
+<REQUIRES>multiplier_2</REQUIRES>
+<REQUIRES>adder</REQUIRES>
+<REQUIRES>constant</REQUIRES>
+<JAVASCRIPT>
+// Solution provided by GitHub user clean99
+
+function cminus(x, y) {
+ const z = make_connector();
+ const u = make_connector();
+ const v = make_connector();
+ constant(-1, u);
+ multiplier(u, y, v);
+ adder(x, v, z);
+ return z;
+}
+
+function cmul(x, y) {
+ const z = make_connector();
+ multiplier(x, y, z);
+ return z;
+}
+
+function cdiv(x, y) {
+ const z = make_connector();
+ const u = make_connector();
+ const v = make_connector();
+ constant(1, v);
+ // y * u = 1 -> u = 1 / y
+ multiplier(y, u, v);
+ multiplier(x, u, z);
+ return z;
+}
+
+function cv(val) {
+ const x = make_connector();
+ constant(val, x);
+ return x;
+}
+</JAVASCRIPT>
+ </SNIPPET>
+ </SOLUTION>
  </EXERCISE>
 
  <INDEX>propagation of constraints<CLOSE/></INDEX>