Questions:


(1) Is AEXP sound. Either provide a proof or give a counter-example


(2) A system is complete iff
    for any expression e and value v if |- e => v then |- e : tau
    for some type tau

(2a) Is AEXP complete. What about ABEXP?



(3) Refining ABEXPs type language

 Consider the expression

       (True ? 1 : False) + 3

This expression is rejected by ABEXPs static semantics although
the dynamic semantics yields a valid result.

Investigate how to extend/refine ABEXPs type language to make
the above expression typable.

What about

tau' ::= Int | Bool | (Int v Bool)


where v stands for boolean disjunction

Will this work?