Written Assignment #2
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Due 3/29 at 11:59pm, submit via Blackboard

In either LaTeX or in a .txt file: 

0) Write separation-logic specifications, in the form of pre- and post-conditions, 
   for the following list-manipulating programs: 

     - list_sum (sums the elements of a null-terminated input list)
     - list_reverse (reverses the elements of a null-terminated input list, as in class)
     - list_append (appends two lists)
     - tree_sum (sums the elements of a binary tree)

    Give complete definitions for any predicates you use in specifications.
    For example, to specify list_sum, you'll need a specification in SL for 
    "List" [a list datastructure in memory] as well a mathematical 
    characterization of sequences.

1) Prove in separation logic -- in the form of an annotated program in an 
   Imp-like imperative language -- that the four programs listed in 0) meet 
   their specifications.

2) Work on your final projects! [0) and 1) should be relatively easy.]