The Hudson Engineering Group (HEG) has contacted you to create a conceptual model whose application will meet the expected database requirements for its training program. The HEG administrator gives you the following description of the training group's operating environment:

The HEG has 12 instructors and can handle up to 30 trainees per class. HEG offers five "advanced technology" courses, each of which may generate several classes. If a class has fewer than 10 trainees in it, it will be canceled. It is, therefore, possible for a course not to generate any classes. Each class is taught by one instructor. Each instructor may teach up to two classes or may be assigned to do research. Each trainee may take up to two classes per year.

Given this information, do the following:

1. Draw the E-R diagram for HEG.
2. Describe the relationship between instructor and course in terms of connectivity, cardinality, and existence dependence.
3. Explain the difference between single-valued attributes and simple attributes. Give an example of each.