diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..9917ead
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,459 @@
+# Byte-compiled / optimized / DLL files
+__pycache__/
+*.py[cod]
+*$py.class
+
+# C extensions
+*.so
+
+# Distribution / packaging
+.Python
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+.eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+wheels/
+share/python-wheels/
+*.egg-info/
+.installed.cfg
+*.egg
+MANIFEST
+
+# PyInstaller
+#  Usually these files are written by a python script from a template
+#  before PyInstaller builds the exe, so as to inject date/other infos into it.
+*.manifest
+*.spec
+
+# Installer logs
+pip-log.txt
+pip-delete-this-directory.txt
+
+# Unit test / coverage reports
+htmlcov/
+.tox/
+.nox/
+.coverage
+.coverage.*
+.cache
+nosetests.xml
+coverage.xml
+*.cover
+*.py,cover
+.hypothesis/
+.pytest_cache/
+cover/
+
+# Translations
+*.mo
+*.pot
+
+# Django stuff:
+*.log
+local_settings.py
+db.sqlite3
+db.sqlite3-journal
+
+# Flask stuff:
+instance/
+.webassets-cache
+
+# Scrapy stuff:
+.scrapy
+
+# Sphinx documentation
+docs/_build/
+
+# PyBuilder
+.pybuilder/
+target/
+
+# Jupyter Notebook
+.ipynb_checkpoints
+
+# IPython
+profile_default/
+ipython_config.py
+
+# pyenv
+#   For a library or package, you might want to ignore these files since the code is
+#   intended to run in multiple environments; otherwise, check them in:
+# .python-version
+
+# pipenv
+#   According to pypa/pipenv#598, it is recommended to include Pipfile.lock in version control.
+#   However, in case of collaboration, if having platform-specific dependencies or dependencies
+#   having no cross-platform support, pipenv may install dependencies that don't work, or not
+#   install all needed dependencies.
+#Pipfile.lock
+
+# poetry
+#   Similar to Pipfile.lock, it is generally recommended to include poetry.lock in version control.
+#   This is especially recommended for binary packages to ensure reproducibility, and is more
+#   commonly ignored for libraries.
+#   https://python-poetry.org/docs/basic-usage/#commit-your-poetrylock-file-to-version-control
+#poetry.lock
+
+# pdm
+#   Similar to Pipfile.lock, it is generally recommended to include pdm.lock in version control.
+#pdm.lock
+#   pdm stores project-wide configurations in .pdm.toml, but it is recommended to not include it
+#   in version control.
+#   https://pdm.fming.dev/#use-with-ide
+.pdm.toml
+
+# PEP 582; used by e.g. github.com/David-OConnor/pyflow and github.com/pdm-project/pdm
+__pypackages__/
+
+# Celery stuff
+celerybeat-schedule
+celerybeat.pid
+
+# SageMath parsed files
+*.sage.py
+
+# Environments
+.env
+.venv
+env/
+venv/
+ENV/
+env.bak/
+venv.bak/
+
+# Spyder project settings
+.spyderproject
+.spyproject
+
+# Rope project settings
+.ropeproject
+
+# mkdocs documentation
+/site
+
+# mypy
+.mypy_cache/
+.dmypy.json
+dmypy.json
+
+# Pyre type checker
+.pyre/
+
+# pytype static type analyzer
+.pytype/
+
+# Cython debug symbols
+cython_debug/
+
+# PyCharm
+#  JetBrains specific template is maintained in a separate JetBrains.gitignore that can
+#  be found at https://github.com/github/gitignore/blob/main/Global/JetBrains.gitignore
+#  and can be added to the global gitignore or merged into this file.  For a more nuclear
+#  option (not recommended) you can uncomment the following to ignore the entire idea folder.
+.idea/
+**/.DS_Store
+out/model/*.pt
+
+## Core latex/pdflatex auxiliary files:
+*.aux
+*.lof
+*.lot
+*.fls
+*.out
+*.toc
+*.fmt
+*.fot
+*.cb
+*.cb2
+.*.lb
+
+## Intermediate documents:
+*.dvi
+*.xdv
+*-converted-to.*
+# these rules might exclude image files for figures etc.
+# *.ps
+# *.eps
+# *.pdf
+
+## Generated if empty string is given at "Please type another file name for output:"
+
+## Bibliography auxiliary files (bibtex/biblatex/biber):
+*.bbl
+*.bcf
+*.blg
+*-blx.aux
+*-blx.bib
+*.run.xml
+
+## Build tool auxiliary files:
+*.fdb_latexmk
+*.synctex
+*.synctex(busy)
+*.synctex.gz
+*.synctex.gz(busy)
+*.pdfsync
+
+## Build tool directories for auxiliary files
+# latexrun
+latex.out/
+
+## Auxiliary and intermediate files from other packages:
+# algorithms
+*.alg
+*.loa
+
+# achemso
+acs-*.bib
+
+# amsthm
+*.thm
+
+# beamer
+*.nav
+*.pre
+*.snm
+*.vrb
+
+# changes
+*.soc
+
+# comment
+*.cut
+
+# cprotect
+*.cpt
+
+# elsarticle (documentclass of Elsevier journals)
+*.spl
+
+# endnotes
+*.ent
+
+*.lox
+
+# feynmf/feynmp
+*.mf
+*.mp
+*.t[1-9]
+*.t[1-9][0-9]
+*.tfm
+
+#(r)(e)ledmac/(r)(e)ledpar
+*.end
+*.?end
+*.[1-9]
+*.[1-9][0-9]
+*.[1-9][0-9][0-9]
+*.[1-9]R
+*.[1-9][0-9]R
+*.[1-9][0-9][0-9]R
+*.eledsec[1-9]
+*.eledsec[1-9]R
+*.eledsec[1-9][0-9]
+*.eledsec[1-9][0-9]R
+*.eledsec[1-9][0-9][0-9]
+*.eledsec[1-9][0-9][0-9]R
+
+# glossaries
+*.acn
+*.acr
+*.glg
+*.glo
+*.gls
+*.glsdefs
+*.lzo
+*.lzs
+*.slg
+*.slo
+*.sls
+
+# uncomment this for glossaries-extra (will ignore makeindex's style files!)
+# *.ist
+
+# gnuplot
+*.gnuplot
+*.table
+
+# gnuplottex
+*-gnuplottex-*
+
+# gregoriotex
+*.gaux
+*.glog
+*.gtex
+
+# htlatex
+*.4ct
+*.4tc
+*.idv
+*.lg
+*.trc
+*.xref
+
+# hyperref
+*.brf
+
+# knitr
+*-concordance.tex
+# *.tikz
+*-tikzDictionary
+
+# listings
+*.lol
+
+# luatexja-ruby
+*.ltjruby
+
+# makeidx
+*.idx
+*.ilg
+*.ind
+
+# minitoc
+*.maf
+*.mlf
+*.mlt
+*.mtc[0-9]*
+*.slf[0-9]*
+*.slt[0-9]*
+*.stc[0-9]*
+
+# minted
+_minted*
+*.pyg
+
+# morewrites
+*.mw
+
+# newpax
+*.newpax
+
+# nomencl
+*.nlg
+*.nlo
+*.nls
+
+# pax
+*.pax
+
+# pdfpcnotes
+*.pdfpc
+
+# sagetex
+*.sagetex.sage
+*.sagetex.py
+*.sagetex.scmd
+
+# scrwfile
+*.wrt
+
+# svg
+svg-inkscape/
+
+# sympy
+*.sout
+*.sympy
+sympy-plots-for-*.tex/
+
+# pdfcomment
+*.upa
+*.upb
+
+# pythontex
+*.pytxcode
+pythontex-files-*/
+
+# tcolorbox
+*.listing
+
+# thmtools
+*.loe
+
+# TikZ & PGF
+*.dpth
+*.md5
+*.auxlock
+
+# titletoc
+*.ptc
+
+# todonotes
+*.tdo
+
+# vhistory
+*.hst
+*.ver
+
+*.lod
+
+# xcolor
+*.xcp
+
+# xmpincl
+*.xmpi
+
+# xindy
+*.xdy
+
+# xypic precompiled matrices and outlines
+*.xyc
+*.xyd
+
+# endfloat
+*.ttt
+*.fff
+
+# Latexian
+TSWLatexianTemp*
+
+## Editors:
+# WinEdt
+*.bak
+*.sav
+
+# Texpad
+.texpadtmp
+
+# LyX
+*.lyx~
+
+# Kile
+*.backup
+
+# gummi
+.*.swp
+
+# KBibTeX
+*~[0-9]*
+
+# TeXnicCenter
+*.tps
+
+# auto folder when using emacs and auctex
+./auto/*
+*.el
+
+# expex forward references with \gathertags
+*-tags.tex
+
+# standalone packages
+*.sta
+
+# Makeindex log files
+*.lpz
+
+# xwatermark package
+*.xwm
+
+# REVTeX puts footnotes in the bibliography by default, unless the nofootinbib
+# option is specified. Footnotes are the stored in a file with suffix Notes.bib.
+# Uncomment the next line to have this generated file ignored.
+#*Notes.bib
\ No newline at end of file
diff --git a/README.md b/README.md
index 7f0f854..69e7888 100644
--- a/README.md
+++ b/README.md
@@ -10,5 +10,12 @@ In this repository, you can find the following files:
 
 Note: Feel free to modify this file according to the project's necessities.
 
+## Environment setup
 
- 
+To install the required dependencies make sure `python3` points to a Python 3.10 or 3.11 installation and then run:
+
+```shell
+python3 -m venv env
+source env/bin/activate
+pip install -r requirements.txt
+```
diff --git a/instrumentor.py b/instrumentor.py
new file mode 100644
index 0000000..7756334
--- /dev/null
+++ b/instrumentor.py
@@ -0,0 +1,145 @@
+from collections import defaultdict
+from dataclasses import dataclass
+from typing import TypeVar, Callable, Optional
+from typing import Generic
+
+from nltk import edit_distance
+
+T = TypeVar('T')
+U = TypeVar('U')
+
+
+@dataclass
+class CmpOp(Generic[T]):
+    operator: str
+    name: str
+    test: Callable[[T, T], bool]
+    true_dist: Callable[[T, T], int]
+    false_dist: Callable[[T, T], int]
+
+    def __init__(self, operator: str, name: str, test: Callable[[T, T], bool], true_dist: Callable[[T, T], int],
+                 false_dist: Callable[[T, T], int]):
+        self.operator = operator
+        self.name = name
+        self.test = test
+        self.true_dist = true_dist
+        self.false_dist = false_dist
+
+
+@dataclass
+class InstrState:
+    min_true_dist: Optional[int]
+    min_false_dist: Optional[int]
+
+    def __init__(self):
+        self.min_true_dist = None
+        self.min_false_dist = None
+
+    def update(self, op: CmpOp[U], lhs: U, rhs: U):
+        true_dist = op.true_dist(lhs, rhs)
+        self.min_true_dist = true_dist if self.min_true_dist is None else min(true_dist, self.min_true_dist)
+
+        false_dist = op.false_dist(lhs, rhs)
+        self.min_false_dist = false_dist if self.min_false_dist is None else min(false_dist, self.min_false_dist)
+
+
+instrumentation_states: defaultdict[int, InstrState] = defaultdict(InstrState)
+
+# Operands for these must both be integers or strings of length 1
+int_str_ops: list[CmpOp[int | str]] = [
+    CmpOp(operator='<',
+          name='Lt',
+          test=lambda lhs, rhs: lhs < rhs,
+          true_dist=lambda lhs, rhs: lhs - rhs + 1 if lhs >= rhs else 0,
+          false_dist=lambda lhs, rhs: rhs - lhs if lhs < rhs else 0),
+    CmpOp(operator='>',
+          name='Gt',
+          test=lambda lhs, rhs: lhs > rhs,
+          true_dist=lambda lhs, rhs: rhs - lhs + 1 if lhs <= rhs else 0,
+          false_dist=lambda lhs, rhs: lhs - rhs if lhs > rhs else 0),
+    CmpOp(operator='<=',
+          name='LtE',
+          test=lambda lhs, rhs: lhs <= rhs,
+          true_dist=lambda lhs, rhs: lhs - rhs if lhs > rhs else 0,
+          false_dist=lambda lhs, rhs: rhs - lhs + 1 if lhs <= rhs else 0),
+    CmpOp(operator='>=',
+          name='GtE',
+          test=lambda lhs, rhs: lhs >= rhs,
+          true_dist=lambda lhs, rhs: rhs - lhs if lhs < rhs else 0,
+          false_dist=lambda lhs, rhs: lhs - rhs + 1 if lhs >= rhs else 0),
+    CmpOp(operator='==',
+          name='Eq',
+          test=lambda lhs, rhs: lhs == rhs,
+          true_dist=lambda lhs, rhs: abs(lhs - rhs),
+          false_dist=lambda lhs, rhs: 1 if lhs == rhs else 0),
+    CmpOp(operator='!=',
+          name='NotEq',
+          test=lambda lhs, rhs: lhs == rhs,
+          true_dist=lambda lhs, rhs: 1 if lhs == rhs else 0,
+          false_dist=lambda lhs, rhs: abs(lhs - rhs)),
+]
+
+int_str_by_name: dict[str, CmpOp[int | str]] = {c.name: c for c in int_str_ops}
+
+
+def int_str_check(a: any, b: any) -> bool:
+    if type(a) == int and type(b) == int:
+        return True
+    if type(a) != str or type(b) != str:
+        return False
+    return len(a) == 1 or len(b) == 1
+
+
+def int_str_convert(x: int | str) -> int:
+    if type(x) == int:
+        return x
+    if len(x) == 1:
+        return ord(x)
+
+    raise ValueError("x must be int or len(str) == 1")
+
+
+# Operands for these must both be strings
+str_ops: list[CmpOp[str]] = [
+    CmpOp(operator='==',
+          name='Eq',
+          test=lambda lhs, rhs: lhs == rhs,
+          true_dist=lambda lhs, rhs: edit_distance(lhs, rhs),
+          false_dist=lambda lhs, rhs: 1 if lhs == rhs else 0),
+    CmpOp(operator='!=',
+          name='NotEq',
+          test=lambda lhs, rhs: lhs == rhs,
+          true_dist=lambda lhs, rhs: 1 if lhs == rhs else 0,
+          false_dist=lambda lhs, rhs: edit_distance(lhs, rhs)),
+]
+
+str_by_name: dict[str, CmpOp[int | str]] = {c.name: c for c in str_ops}
+
+
+def str_check(a: any, b: any) -> bool:
+    return type(a) == str and type(b) == str
+
+
+def evaluate_condition(cmp_id: int, name: str, lhs: any, rhs: any) -> bool:
+    if int_str_check(lhs, rhs):
+        lhs_int = int_str_convert(lhs)
+        rhs_int = int_str_convert(rhs)
+
+        if name not in int_str_by_name:
+            raise ValueError(f"'{name}' is not a valid CmpOp name for 'int_str' operators")
+
+        op = int_str_by_name[name]
+
+        instrumentation_states[cmp_id].update(op, lhs_int, rhs_int)
+        return op.test(lhs_int, rhs_int)
+
+    if str_check(lhs, rhs):
+        if name not in str_by_name:
+            raise ValueError(f"'{name}' is not a valid CmpOp name for 'str' operators")
+
+        op = int_str_by_name[name]
+
+        instrumentation_states[cmp_id].update(op, lhs, rhs)
+        return op.test(lhs, rhs)
+
+    raise ValueError(f"'{lhs}' and '{rhs}' are not suitable for both 'int_str' and 'str' operators")
diff --git a/requirements.txt b/requirements.txt
new file mode 100644
index 0000000..1a170a4
--- /dev/null
+++ b/requirements.txt
@@ -0,0 +1 @@
+nltk==3.8.1
\ No newline at end of file