Programming Languages, Fall 2013
HW9 - Simple Extensions to Simply-Typed Lambda-Calculus

Due electronically on Blackboard on Wednesday November 20, 11:59pm.

1. 11.4.1 in TAPL (ascription as derived form).

2. 11.5.2 in TAPL (eager let).

3. 11.8.2 in TAPL (record matching).

4. 11.9.1 in TAPL (case for if)

5. Create an example of variant type term, show its typing derivation tree,
   and show its (one-step) evaluation sequence until it reaches a value.

6. Write the big-step evaluation rules for both record and variant types.

Debriefing (required!): --------------------------

1. Approximately how many hours did you spend on this assignment?
2. Would you rate it as easy, moderate, or difficult?
3. Did you work on it mostly alone, or mostly with other people?
4. How deeply do you feel you understand the material it covers (0%–100%)? 
5. Any other comments?

This section is intended to help us calibrate the homework assignments. 
Your answers to this section will *not* affect your grade; however, skipping it
will certainly do.