Based on the provided constraints, there are a few potential anomalies and contradictions in the model:

1. The 'Absence' constraint is specified for activities that are not mentioned in any other constraints. It would be more meaningful if the absence constraint was applied to the activities that are present in other constraints.

2. There are contradictions between the 'Co-Existence' constraint and the 'Alternate Succession' constraint. For example, ('Request Payment', 'Payment Handled') is in both constraints, but alternate succession implies that these activities cannot directly follow each other, which contradicts the co-existence constraint.

3. Similarly, there are contradictions between the 'Co-Existence' constraint and the 'Non Co-Existence' constraint. These constraints are mutually exclusive and cannot both be true for the same pair of activities.

4. The 'Chain Response' and 'Chain Precedence' constraints are only specified for ('Declaration FINAL_APPROVED by SUPERVISOR', 'Request Payment') and ('Request Payment', 'Payment Handled'), respectively. However, the 'Chain Succession' constraint includes ('Declaration FINAL_APPROVED by SUPERVISOR', 'Payment Handled'), which is not covered by the chain response or chain precedence constraints.

5. The 'Responded Existence' constraint is specified for many pairs of activities, including some that contradict other constraints. For example, ('Request Payment', 'Payment Handled') and ('Payment Handled', 'Request Payment') contradict the 'Alternate Succession' constraint.

These anomalies suggest that the constraints may need to be revised to ensure consistency and avoid contradictions.