diff --git a/.devcontainer/Dockerfile b/.devcontainer/Dockerfile
new file mode 100644
index 0000000..455dbfa
--- /dev/null
+++ b/.devcontainer/Dockerfile
@@ -0,0 +1,22 @@
+FROM sjkillen/clyngor
+
+RUN apt-get -qq update; apt-get -qq install sudo
+
+ARG USERNAME=asp
+ARG USER_UID=1000
+ARG USER_GID=$USER_UID
+
+# Copied from https://code.visualstudio.com/docs/remote/containers-advanced#_adding-a-nonroot-user-to-your-dev-container
+
+# Create the user
+RUN groupadd --gid $USER_GID $USERNAME \
+    && useradd --uid $USER_UID --gid $USER_GID -m $USERNAME --shell /bin/bash \
+    #
+    # [Optional] Add sudo support. Omit if you don't need to install software after connecting.
+    && echo $USERNAME ALL=\(root\) NOPASSWD:ALL > /etc/sudoers.d/$USERNAME \
+    && chmod 0440 /etc/sudoers.d/$USERNAME
+
+
+USER $USERNAME
+
+ENTRYPOINT ["bash"]
diff --git a/.devcontainer/devcontainer.json b/.devcontainer/devcontainer.json
new file mode 100644
index 0000000..2090cc0
--- /dev/null
+++ b/.devcontainer/devcontainer.json
@@ -0,0 +1,34 @@
+// For format details, see https://aka.ms/vscode-remote/devcontainer.json or this file's README at:
+// https://github.com/microsoft/vscode-dev-containers/tree/v0.117.0/containers/docker-existing-dockerfile
+{
+	"name": "Clyngor setup",
+
+	// Sets the run context to one level up instead of the .devcontainer folder.
+	"context": "..",
+
+	// Update the 'dockerFile' property if you aren't using the standard 'Dockerfile' filename.
+	"dockerFile": "./Dockerfile",
+
+	// Set *default* container specific settings.json values on container create.
+	"settings": { 
+		"terminal.integrated.shell.linux": null
+	},
+
+	// Add the IDs of extensions you want installed when the container is created.
+	"extensions": ["abelcour.asp-syntax-highlight", "ms-python.python"]
+
+	// Use 'forwardPorts' to make a list of ports inside the container available locally.
+	// "forwardPorts": [],
+
+	// Uncomment the next line to run commands after the container is created - for example installing git.
+	// "postCreateCommand": "apt-get update && apt-get install -y git",
+
+	// Uncomment when using a ptrace-based debugger like C++, Go, and Rust
+	// "runArgs": [ "--cap-add=SYS_PTRACE", "--security-opt", "seccomp=unconfined" ],
+
+	// Uncomment to use the Docker CLI from inside the container. See https://aka.ms/vscode-remote/samples/docker-in-docker.
+	// "mounts": [ "source=/var/run/docker.sock,target=/var/run/docker.sock,type=bind" ],
+
+	// Uncomment to connect as a non-root user. See https://aka.ms/vscode-remote/containers/non-root.
+	// "remoteUser": "vscode"
+}
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..bfa6551
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+notes
diff --git a/.vscode/settings.json b/.vscode/settings.json
new file mode 100644
index 0000000..afb940f
--- /dev/null
+++ b/.vscode/settings.json
@@ -0,0 +1,3 @@
+{
+    "discord.enabled": true
+}
\ No newline at end of file
diff --git a/ontology.py b/ontology.py
new file mode 100644
index 0000000..960b4ed
--- /dev/null
+++ b/ontology.py
@@ -0,0 +1,19 @@
+from typing import Set
+
+models = (
+    {"a", "b", "c"},
+)
+
+DL_ATOMS = set.union(*models)
+
+def propagate(atoms: Set[str]) -> Set[str]:
+    atoms = atoms.intersection(DL_ATOMS)
+    sub_models = (model for model in models if atoms <= model)
+    first: set = next(sub_models, None)
+    if first is None:
+        return set()
+    return first.intersection(*sub_models)
+
+def check(atoms: Set[str]) -> bool:
+    atoms = atoms.intersection(DL_ATOMS)
+    return atoms in models
diff --git a/propagator.py b/propagator.py
new file mode 100644
index 0000000..97fbaeb
--- /dev/null
+++ b/propagator.py
@@ -0,0 +1,136 @@
+from copy import deepcopy
+from itertools import chain
+from operator import itemgetter
+from typing import Iterable, List, Tuple
+import clingo
+from clingo import PropagateControl, PropagateInit, PropagateControl, PropagatorCheckMode, Assignment, Symbol, Control, TheoryAtom
+
+import ontology as O
+
+
+class Ontology:
+    def init(self, init: PropagateInit) -> None:
+        init.check_mode = PropagatorCheckMode.Total
+       
+        self.assignment = dict()
+
+        self.symbolic_atoms = {
+            init.solver_literal(atom.literal): str(atom.symbol)
+            for atom in init.symbolic_atoms
+        }
+        self.theory_atoms = {
+            init.solver_literal(atom.literal): atom.elements[0].terms[0].name
+            for atom in init.theory_atoms
+        }
+        self.symbolic_atoms_inv = { v: k for k, v in self.symbolic_atoms.items() }
+        self.theory_atoms_inv = { v: k for k, v in self.theory_atoms.items() }
+
+
+        # Might only need to watch just theory atoms / just symbol atoms but for now
+        # watching everything is easier 
+        for lit in chain(self.symbolic_atoms, self.theory_atoms):
+            init.add_watch(lit)
+
+
+    def truthy_atoms_text(self):
+        return (str(self.lookup_solver_lit(atom)[0]) for atom in self.assignment if self.assignment[atom])
+
+    def atom_text_to_dl_atom(self, atoms: Iterable[str]) -> Iterable[int]:
+        return map(self.theory_atoms.get, atoms)
+
+    def falsey_atoms_text(self):
+        return (str(self.lookup_solver_lit(atom)[0]) for atom in self.assignment if not self.assignment[atom])
+
+    def propagate(self, pcontrol: PropagateControl, changes) -> None:
+        for change in changes:
+            atom = abs(change)
+            assert atom not in self.assignment
+            self.assignment[atom] = change >= 0
+        
+        in_atoms = set(self.truthy_atoms_text())
+        out_atoms = self.atom_text_to_dl_atom(O.propagate())
+        new_atoms = out_atoms - in_atoms
+        new_lits = self.atom_text_to_dl_atom(new_atoms)
+
+
+
+    def undo(self, thread_id: int, assignment: Assignment, changes: List[int]):
+        for change in changes:
+            atom = abs(change)
+            del self.assignment[atom]
+
+    def check(self, pcontrol: PropagateControl) -> None:
+        self.print_assignment()
+
+
+    def print_assignment(self):
+        print("assignment: ", end="")
+        for lit in self.assignment:
+            lit = -lit if not self.assignment[lit] else lit
+            print(self.solver_lit_text(lit), end=" ")
+        print()
+
+    def is_theory_atom(self, lit: int):
+        _, _, a = self.lookup_solver_lit(lit)
+        return a
+
+    def solver_lit_text(self, lit: int):
+        symbol, is_neg, is_theory = self.lookup_solver_lit(lit)
+        if symbol is None:
+            return None
+        theory = "O: " if is_theory else ""
+        neg = "not " if is_neg else ""
+        return f"({theory}{neg}{symbol})"
+
+
+    def lookup_solver_lit(self, lit: int) -> Tuple[Symbol, bool, bool]:
+        atom = abs(lit)
+        if (atom_symb := self.symbolic_atoms.get(atom, None)) is not None:
+            return atom_symb, lit < 0, False
+        if (theo_symbol := self.theory_atoms.get(atom, None)) is not None:
+            return theo_symbol, lit < 0, True
+        return None, False, False
+
+
+program="""
+a :- not b.
+b :- not a.
+c :- not d.
+"""
+
+# Need to ground program before we can look up symbolic atoms and
+# Having two waves of grounding might be having some weird effects
+# So we parse and ground and then revert back to text then reparse
+def add_external_atoms(program: str) -> str:
+    control = clingo.Control(["0"])
+    control.add("base", [], program)
+    control.ground([("base", [])])
+
+    theory_grammar = """
+#theory o {
+    kterm {- : 0, unary };
+    &o/0 : kterm, any
+}.
+    """
+    external_atoms = "\n".join(
+        f"{atom} :- &o{{{atom}}}." for atom in 
+        (str(atom.symbol) for atom in control.symbolic_atoms)
+    )
+    return theory_grammar + program + external_atoms
+
+
+program = add_external_atoms(program)
+control = clingo.Control(["0"])
+propagator = Ontology()
+control.register_propagator(propagator)
+control.add("base", [], program)
+control.ground([("base", [])])
+
+# control.add("external", [], theory_grammar + external_atoms)
+
+# control.ground([("external", [])])
+
+with control.solve(yield_=True) as solve_handle:
+    for model in solve_handle:
+        print("answer set:", model)
+