def reward_function(response, context):
    score = 0.0
    if uses_context(response, context):
        score += 0.4
    if not has_hallucination(response, context):
        score += 0.3
    if is_complete(response, context):
        score += 0.2
    if is_concise(response):
        score += 0.1
    return score