Based on prior knowledge, the feature "IBS_POST" represents the presence of coronary heart disease (CHD) in recent weeks before the patient's admission to the hospital. The categories of the feature include:

- "there was no СHD"
- "exertional angina pectoris"
- "unstable angina pectoris"

To determine if the patient has chronic heart failure (CHF), we need to analyze the relationship between the feature "IBS_POST" and the target variable of CHF complications.

To create the dictionary, we need to identify the values of "IBS_POST" for each target class ("yes" or "no) separately. Let's analyze the relationship:

For the target class "no" (patients without CHF complications):

- There may be cases where CHD was not present before admission to the hospital ("there was no СHD"), indicating a lower risk of CHF.

For the target class "yes" (patients with CHF complications):

- Patients who experienced exertional angina pectoris or unstable angina pectoris may have a higher likelihood of developing CHF.

Based on this analysis, we can generate the following dictionary:

```json
{
	"no": ["there was no СHD"],
	"yes": ["exertional angina pectoris", "unstable angina pectoris"]
}
```

Please note that this analysis assumes a simplified relationship between "IBS_POST" and the occurrence of CHF complications, based on prior knowledge. The actual relationship may depend on various other factors and should be further validated and refined with more data and domain expertise.