Name: ###@###.### Date: 09/05/96

a variable is not considered as definitely assigned after
             the boolean operator != when false. Meanwhile, in one case it
             is definitely assigned after its left operand when true and
             after its right operand when false. In the other case, vice
             versa, it is definitely assigned after the left operand when
             false and after the right operand when true. This contradicts
             the following assertions:

             The rules for a != b are identical to the rules for a ^ b.

             (Java Language Specification, section 16.1.10)

             V is definitely assigned after a ^ b when true iff at least
             one of the following is true:

             - V is definitely assigned after b.
             - V is definitely assigned after a when true and V is definitely
               assigned after b when false.
             - V is definitely assigned after a when false and V is definitely
               assigned after b when true.

             (Java Language Specification, section 16.1.8)

Test: compilation of the following test

public class test
{
public static void main(String argv[])
{
boolean b;
boolean r = false;
boolean t = true;

if ((t && (b = r)) != (r || (b = false)));
else
r = b;
System.out.println(r);
if ((r || (b = t)) != (t && (b = true)));
else
r = b;
System.out.println(r);
}
}

produces such diagnostics:

novo40% javac test.java
test.java:11: Variable b may not have been initialized.
r = b;
^
test.java:15: Variable b may not have been initialized.
r = b;
^
2 errors

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