diff --git a/src/iter.rs b/src/iter.rs
new file mode 100644
index 0000000..da310a1
--- /dev/null
+++ b/src/iter.rs
@@ -0,0 +1,60 @@
+use crate::{Address, Region};
+
+/// Iterator producing block-region pairs, where each memory block maps to each
+/// region.
+pub struct OverlapIterator<'a, R, I>
+where
+	R: Region,
+	I: Iterator<Item = R>,
+{
+	memory: &'a [u8],
+	regions: I,
+	base_address: Address,
+}
+
+/// Trait allowing us to automatically add an `overlaps` function to all iterators over [`Region`]
+pub trait IterableByOverlaps<'a, R, I>
+where
+	R: Region,
+	I: Iterator<Item = R>,
+{
+	/// Obtain an [`OverlapIterator`] over a subslice of `memory` that overlaps with the region in `self`
+	fn overlaps(self, memory: &'a [u8], base_address: Address) -> OverlapIterator<R, I>;
+}
+
+impl<'a, R, I> Iterator for OverlapIterator<'a, R, I>
+where
+	R: Region,
+	I: Iterator<Item = R>,
+{
+	type Item = (&'a [u8], R, Address);
+
+	fn next(&mut self) -> Option<Self::Item> {
+		while let Some(region) = self.regions.next() {
+			//  TODO: This might be possible to do in a smarter way?
+			let mut block_range = (0..self.memory.len())
+				.skip_while(|index| !region.contains(self.base_address + *index))
+				.take_while(|index| region.contains(self.base_address + *index));
+			if let Some(start) = block_range.next() {
+				let end = block_range.last().unwrap_or(start) + 1;
+				return Some((&self.memory[start..end], region, self.base_address + start));
+			}
+		}
+		None
+	}
+}
+
+/// Blanket implementation for all types implementing [`Iterator`] over [`Regions`]
+impl<'a, R, I> IterableByOverlaps<'a, R, I> for I
+where
+	R: Region,
+	I: Iterator<Item = R>,
+{
+	fn overlaps(self, memory: &'a [u8], base_address: Address) -> OverlapIterator<R, I> {
+		OverlapIterator {
+			memory,
+			regions: self,
+			base_address,
+		}
+	}
+}
diff --git a/src/lib.rs b/src/lib.rs
index f528d79..ff86488 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -11,25 +11,11 @@
 #![deny(missing_docs)]
 #![deny(unsafe_code)]
 
-use core::ops::{Add, BitOr, Sub};
+use core::ops::{Add, Sub};
 use nb;
 
-/// Trait to check if two entities are bitwise subset of another.
-pub trait BitSubset {
-	/// Check that every '1' bit is a '1' on the right hand side.
-	fn is_subset_of(&self, rhs: &Self) -> bool;
-}
-
-/// Blanket implementation of [`BitSubset`] for all arrays of a type implementing [`BitOr`]
-impl<T: Copy + Eq + BitOr<Output = T>> BitSubset for [T] {
-	fn is_subset_of(&self, rhs: &Self) -> bool {
-		if self.len() > rhs.len() {
-			false
-		} else {
-			self.iter().zip(rhs.iter()).all(|(a, b)| (*a | *b) == *b)
-		}
-	}
-}
+/// Currently contains [`OverlapIterator`]
+pub mod iter;
 
 /// An address denotes the read/write address of a single word.
 #[derive(Default, Copy, Clone, Debug, PartialOrd, PartialEq, Eq, Ord)]
@@ -43,11 +29,26 @@ impl Add<usize> for Address {
 	}
 }
 
-impl Add<Address> for Address {
+impl Add<isize> for Address {
+	type Output = Self;
+
+	fn add(self, rhs: isize) -> Self::Output {
+		Address((self.0 as isize + rhs) as u32)
+	}
+}
+impl Sub<usize> for Address {
 	type Output = Self;
 
-	fn add(self, rhs: Address) -> Self::Output {
-		Address(self.0 + rhs.0)
+	fn sub(self, rhs: usize) -> Self::Output {
+		Address(self.0 - rhs as u32)
+	}
+}
+
+impl Sub<isize> for Address {
+	type Output = Self;
+
+	fn sub(self, rhs: isize) -> Self::Output {
+		Address((self.0 as isize - rhs) as u32)
 	}
 }
 
@@ -65,69 +66,6 @@ pub trait Region {
 	fn contains(&self, address: Address) -> bool;
 }
 
-/// Iterator producing block-region pairs, where each memory block maps to each
-/// region.
-pub struct OverlapIterator<'a, R, I>
-where
-	R: Region,
-	I: Iterator<Item = R>,
-{
-	memory: &'a [u8],
-	regions: I,
-	base_address: Address,
-}
-
-/// Trait allowing us to automatically add an `overlaps` function to all iterators over [`Region`]
-pub trait IterableByOverlaps<'a, R, I>
-where
-	R: Region,
-	I: Iterator<Item = R>,
-{
-	/// Obtain an [`OverlapIterator`] over a subslice of `memory` that overlaps with the region in `self`
-	fn overlaps(self, memory: &'a [u8], base_address: Address) -> OverlapIterator<R, I>;
-}
-
-impl<'a, R, I> Iterator for OverlapIterator<'a, R, I>
-where
-	R: Region,
-	I: Iterator<Item = R>,
-{
-	type Item = (&'a [u8], R, Address);
-
-	fn next(&mut self) -> Option<Self::Item> {
-		while let Some(region) = self.regions.next() {
-			//  TODO: This might be possible to do in a smarter way?
-			let mut block_range = (0..self.memory.len())
-				.skip_while(|index| !region.contains(self.base_address + Address(*index as u32)))
-				.take_while(|index| region.contains(self.base_address + Address(*index as u32)));
-			if let Some(start) = block_range.next() {
-				let end = block_range.last().unwrap_or(start) + 1;
-				return Some((
-					&self.memory[start..end],
-					region,
-					self.base_address + Address(start as u32),
-				));
-			}
-		}
-		None
-	}
-}
-
-/// Blanket implementation for all types implementing [`Iterator`] over [`Regions`]
-impl<'a, R, I> IterableByOverlaps<'a, R, I> for I
-where
-	R: Region,
-	I: Iterator<Item = R>,
-{
-	fn overlaps(self, memory: &'a [u8], base_address: Address) -> OverlapIterator<R, I> {
-		OverlapIterator {
-			memory,
-			regions: self,
-			base_address,
-		}
-	}
-}
-
 /// Storage trait
 pub trait ReadWrite {
 	/// An enumeration of storage errors