Currently the expected translation function works for constants. This
needs to be extended for other term types.

The robustness of the type inference can also be improved on.
Currently the new type is generated by appending new elements to a list
which has an implicit ordering.

Basic testcases work with valid typing.

To do:
  -- Add type-checking to provide an error when set functions cannot be
translated
  -- Add other cases

Appart from creating the standard ml framework for input files for
s-expressions, the majority of the testing with the small language is
complete.

To do:
  - Start translating the main project

Script added parses an s-expression into a statement in the defined
lanugage. Translation is successful. (Note: do notation in function
definitions will not translate)

To do:
  - Create test cases for the s-expression parser
  - Create a parser for enviromental variables
  - Create framework for inputing s-expressions in sml

Bugs fixed are the missing case in the schedule script.
Naming inconsistencies were rectified in the different scripts.
The folder hierarchy was also fixed.

The extExprScript.sml theorem has successfully been able to create a
translation file which has sml code in it.

A seperate script file was created where all the translation of HOL4
code will occur. Another script file will then translate that code from
a theorem to an output .ml.txt file.

Things To Do:
  -- Translate the reset of the files
  -- Remove the translation commands in the original script files

Attempts in proofs also in comments

The new symbolic computation system finally works! Factorial runs again, albeit
slower than before. Load/Store isn't working yet, but only because global cells
aren't preallocated.

Because the Mu spec says that newly-allocated memory locations are zeroed out,
option values for unallocated spaces in data structures have been removed, and
newly-allocated values are filled with 0/NULL.

The "translate" function was called on the find_steps function and the
eval_n_steps function. Holmake did not return an error so the
compatibility of the HOL functions to cakeml is assumed to be good.

Notes:
  -- When functions in HOL are being translated all functions within
that function must be previously translated explicitly.
  -- It seems that CakeML does not translate lambda expressions well.
  -- Functions must be translated explicitly again when calling from
another library/script

Things To Do:
  -- Compile the HOL code using CakeML.
  -- Explore S-expressions.
  -- Fix the fibonacci test, it partially works but fib_n_def does not
seem to evaluate down to a number, only some-kind of expression format.
  -- Prove some properties about the expression language.

Have gotten the evaluation functions to translate currently.
The fibonacci test in the test script is broken currently.

Things To Do:
  - Translate the scheduler with CakeML tools
  - Fix the fibonacci test script
  - Edit the Holmakefile such that it can be more general for CakeML
      directory location
  - Add test scripts for scheduler
  - Prove correctness of scheduler evaluation

Now will find steps to execute on a program without excessive re-evaluation.

The symbolic value monad was too general, making it impossible to prove
anything useful about it. For example, a symbolic value could become
unresolvable in response to a new resolved value being added to the context,
making recursive resolution loop forever.

In order to prove that resolution terminates, symbolic was changed to an
applicative. The new symbolic type keeps a list of all locations that it depends
on, including a special case for "the last value of this memory location before
this action".

This commit only contains changes to uvmMemoryTheory and its dependencies.
uvmThreadSemantics and uvmScheduler are not done yet, and do not compile.

Have a function which will evaluate a program by generating a schedule
for it to use. Currently generating the schedule is very slow.

Things to do:
  - optimize the schedule function

"Cheating" issue resolved

Still states "cheated" on Holmake.

Made relevent changes in test script

Fibonacci test was added to the test file.
General debugging while testing.

Things to do:
  - Possible "Free" and "Halt/Fin" constructors for the expression
    language
  - Factorial Test

Mirrored the stylistic changes made in previous commits.
The new structure of evaluation is:

eval_scheduler
  - eval_step
      - eval_xpr_step
      - eval_bool_step

where eval_xpr_step and eval_bool_step are side effect free.

Things to do:
  - Create test cases for correctness
    - Factorial Function