Based on prior knowledge, let's analyze the relationship between the feature "STENOK_AN" and the task of identifying chronic heart failure in patients.

Given that "STENOK_AN" represents the presence of exertional angina pectoris in the patient's medical history, it is possible that patients with chronic heart failure may have a higher incidence of angina in their medical history. However, this relationship is not deterministic and could vary depending on various factors such as the severity of heart failure and individual health conditions.

To create the dictionary, we will analyze the relationship between the feature and the task by examining the "STENOK_AN" values for both the "yes" and "no" classes of chronic heart failure.

- For the "yes" class (chronic heart failure), possible values of "STENOK_AN" that may be relevant include:
  - 'never': It is possible for patients with chronic heart failure to have never experienced exertional angina pectoris in their medical history.
  - 'during the last year': Patients with chronic heart failure may have experienced exertional angina pectoris in the last year.
  - (Additional values could be included based on the available data)

- For the "no" class (no chronic heart failure), since the question does not specify hard-to-predict values, we can assume more common scenarios in which chronic heart failure is not present. For example, possible values of "STENOK_AN" for the "no" class could include:
  - 'never': Patients without chronic heart failure may have never experienced exertional angina pectoris in their medical history.
  - 'more than 5 years ago': Patients without chronic heart failure may have experienced exertional angina pectoris more than 5 years ago.
  - '4-5 years ago': Patients without chronic heart failure may have experienced exertional angina pectoris 4-5 years ago.
  - (Additional values could be included based on the available data)

Based on this analysis, we can construct the dictionary with the following format:

```json
{
	"no": ["never", "more than 5 years ago", "4-5 years ago"],
	"yes": ["never", "during the last year"]
}
```

Please note that the values included in the dictionary are just samples based on common scenarios and should be adjusted based on the specific data and analysis.