YAZ_CHECK(compare(ct, "@or a @and b c", "a OR (b AND c)"));
YAZ_CHECK(compare(ct, "abc", "abc"));
YAZ_CHECK(compare(ct, "\"a b c\"", "\"a b c\""));
+ YAZ_CHECK(compare(ct, "\"\"", "\"\""));
YAZ_CHECK(compare(ct, "@not a b", "a AND NOT b"));
YAZ_CHECK(compare(ct, "@and @or a b c", "(a OR b) AND c"));
YAZ_CHECK(compare(ct, "@and a b", "a AND b"));