diff --git a/src/atoms.py b/src/atoms.py
new file mode 100644
index 0000000..8723803
--- /dev/null
+++ b/src/atoms.py
@@ -0,0 +1,133 @@
+from functools import reduce
+import itertools
+from typing import Generator, Iterable, NamedTuple, Protocol
+from collections.abc import Sized
+
+class SupplyAtom(NamedTuple):
+    identifier: str
+    description: str
+
+    # only consider the identifier field when hashing or comparing
+    def __hash__(self) -> int:
+        return self.identifier.__hash__()
+    def __eq__(self, __o: object) -> bool:
+        return self.identifier == __o.identifier
+
+class Supplier(NamedTuple):
+    name: str
+    supplies: frozenset[SupplyAtom]
+    
+    @staticmethod
+    def create(name: str, supplies: Iterable[SupplyAtom]):
+        return Supplier(name, frozenset(supplies))
+
+class Maker(NamedTuple):
+    name: str
+    tools: frozenset[SupplyAtom]
+
+    @staticmethod
+    def create(name: str, tools: Iterable[SupplyAtom]):
+        return Maker(name, frozenset(tools))
+
+    def compatible(self, tools: Iterable[SupplyAtom]):
+        for tool in tools:
+            if tool not in self.tools:
+                return False
+        return True
+
+class ProductDesign(NamedTuple):
+    product: SupplyAtom
+    bom: frozenset[SupplyAtom]
+    tools: frozenset[SupplyAtom]
+    bomOutputs: frozenset[SupplyAtom]
+
+    @staticmethod
+    def create(product: SupplyAtom, bom: Iterable[SupplyAtom], tools: Iterable[SupplyAtom], bomOutput: Iterable[SupplyAtom]):
+        return ProductDesign(product, frozenset(bom), frozenset(tools), frozenset(bomOutput))
+
+class SupplyTree(Protocol):
+    def getProduct() -> SupplyAtom:
+        ...
+    def print(indent:int):
+        ...
+
+class SupplierSupplyTree(NamedTuple):
+    product: SupplyAtom
+    supplier: Supplier
+
+    def getProduct(self):
+        return self.product
+
+    def print(self, indent: int):
+        buffer = ' ' * indent
+        print(buffer + "Supplier: {}/{}".format(self.supplier.name, self.product.description))
+
+class MakerSupplyTree(NamedTuple):
+    product: SupplyAtom
+    design: ProductDesign
+    maker: Maker
+    supplies: frozenset[SupplyTree]
+
+    def getProduct(self):
+        return self.product
+
+    def print(self, indent: int):
+        buffer = ' ' * indent
+        print(buffer + "Maker: {}/{}".format(self.maker.name, self.design.product.description))
+        for s in self.supplies:
+            s.print(indent + 1)
+
+class SupplyProblemSpace(NamedTuple):
+    suppliers: frozenset[Supplier]
+    makers: frozenset[Maker]
+    designs: frozenset[ProductDesign]
+
+    @staticmethod
+    def create(suppliers: Iterable[Supplier], makers: Iterable[Maker], designs: Iterable[ProductDesign]):
+        return SupplyProblemSpace(frozenset(suppliers), frozenset(makers), frozenset(designs))
+
+    def query(self, product: SupplyAtom) -> Generator[SupplyTree, None, None]:
+        for supplier in self.suppliers:
+            for supply in supplier.supplies:
+                if supply == product:
+                    yield SupplierSupplyTree(product, supplier)
+        for design in self.designs:
+            if design.product == product:
+                inputTrees = map(lambda b: self.query(b), design.bom)
+                inputTreeSet = frozenset(itertools.chain.from_iterable(inputTrees))
+                for maker in self.makers:
+                    if maker.compatible(design.tools):
+                        yield MakerSupplyTree(product, design, maker, inputTreeSet)
+
+
+# Mask Sample
+
+# Product atoms
+fabricMask = SupplyAtom("QH00001", "Fabric Mask")
+
+# BOM atoms
+nwpp = SupplyAtom("QH00002", "Non-woven Polypropylene bag")
+biasTape = SupplyAtom("Q4902580", "Bias tape")
+tinTie = SupplyAtom("QH00003", "Coffee tin tie")
+pipeCleaner = SupplyAtom("Q3355092", "pipe cleaners")
+
+# Tool Atoms
+sewingMachine = SupplyAtom("Q49013", "Sewing machine")
+scissors = SupplyAtom("Q40847", "Scissors")
+pins = SupplyAtom("Q111591519", "Pins")
+measuringTape = SupplyAtom("Q107196205", "Measuring Tape")
+
+# BOM Output Atoms
+scrapFabric = SupplyAtom("Q1378670", "Scrap Fabric")
+
+supplierRaw = Supplier.create("raw supplies",  [nwpp, biasTape, tinTie, pipeCleaner])
+makerJames = Maker.create("James Maker Space", [sewingMachine, scissors, pins, measuringTape])
+designMask = ProductDesign.create(
+    fabricMask, 
+    [nwpp, biasTape, tinTie, pipeCleaner], 
+    [sewingMachine, scissors, pins, scissors],
+    [scrapFabric])
+
+problemSpace = SupplyProblemSpace.create([supplierRaw], [makerJames], [designMask])
+for t in problemSpace.query(fabricMask):
+    t.print(0)