The purpose of this problem is to develop a CESK machine for the
`ISWIM*s`

language from problem set 6. Your CESK machine must
use the store to safe-keep *all* values.

**Task 1**
Encode your CESK machine in Redex.

**Task 2**
Define the `cesk`

function, which uses the CESK machine to
map `ISWIM*s`

programs to answers.

**Task 3**
Formulate a conjecture about the relationship between `eval*-s`

(solution for problem set 6, imported from 8provided.rkt) and
`cesk`

as a metafunction. Test the conjecture manually and with
`redex-check`

.

If testing finds a counter-example to your conjecture, formulate the
counter-example as a failing test case and explain the failure with a
one-line comment. Then fix those parts of your solution that broke so that
the test case passes.

**Task 4**
Fix up your `cek`

function from problem
set 8 (task 2), formulate a conjecture about the relationship between
`cesk`

and `cek`

, and test the conjecture with
`redex-check`

.