svoid test_philosophyBot1_trails() {
  test_philosophyBot1_trailsForLogicRules();
  test_philosophyBot1_trailsForFacts();
}

svoid test_philosophyBot1_trailsForFacts() {
  PhilosophyBot1 bot = new([[
    a => b
    
    a & b => c
    
    a
    
    expect c
  ]]);
  bot.printStackTraces = true;
  bot.enableTrails();
  bot.runAndCheckExpectations();
  for (WithTrail<S> fact : bot.deducedFactsWithTrails())
    assertNotNull("trail for " + fact, fact.trail);
}

svoid test_philosophyBot1_trailsForLogicRules() {
  PhilosophyBot1 bot = new([[
    a & b => c
    
    a
  ]]);
  bot.printStackTraces = true;
  bot.enableTrails();
  bot.think();
  for (PhilosophyBot1.LogicRule rule : bot.logicRules()) {
    print(rule + ", trail: " + rule.trail);
    assertNotNull("trail" , rule.trail);
  }
}