CMSC 221/321
Homework set 6
Due: Tuesday, Nov 23, 2010

6.1 [25]: Write an SML implementation of a CBV, big-step,
environment-based evaluator for TFun + products, sums, and recursive
types (call this TFun_PSR).  This implementation can be based on the
code in tfun.tgz, which implements TFun+products.

6.2 [25]: Write a type-checker for TFun_PSR.  This will extend the
type checker for TFun that you wrote for Hw 4.4 (see tfuntype.sml in
the package tfun.tgz for a type checker covering products).

[11/21/2010: This is a revised version dropping polymorphism from the
language.

11/22/2010: Revised again to mention tfuntype.sml in 5.2.]