// db contains multiple lines of logic rules, first rule is used to
// feed, rest to test
svoid ai_testRuleOfThreeGivingFirst(IF2<S> f, S db, O... _) {
  optPar bool dontTestFirst;
  L<BasicLogicRule<S>> l = parseLogicRules_tlft(db);
  for (BasicLogicRule<S> r : dontTestFirst ? dropFirst(l) : l)
    testFunctionValueIC(f, first(tlft(db)), r.lhs, r.rhs);
}