diff --git a/0044-the-many-faces-of-flatmap-pt3/README.md b/0044-the-many-faces-of-flatmap-pt3/README.md
index bb448a81..4b78e648 100644
--- a/0044-the-many-faces-of-flatmap-pt3/README.md
+++ b/0044-the-many-faces-of-flatmap-pt3/README.md
@@ -1,6 +1,6 @@
 ## [Point-Free](https://www.pointfree.co)
 
-> #### This directory contains code from Point-Free Episode: [The Many Faces of Flat-Map: Part 2](https://www.pointfree.co/episodes/ep43-the-many-faces-of-flat-map-part-2)
+> #### This directory contains code from Point-Free Episode: [The Many Faces of Flat-Map: Part 3](https://www.pointfree.co/episodes/ep44-the-many-faces-of-flat-map-part-3)
 >
 > We are now ready to answer the all-important question: what's the point? We will describe 3 important ideas that are now more accessible due to our deep study of `map`, `zip` and `flatMap`. We will start by showing that this trio of operations forms a kind of functional, domain-specific language for data transformations.
 
@@ -9,6 +9,6 @@
 * Clone repo
 * `cd` into this directory
 * Run `swift package generate-xcodeproj`
-* Open `ManyFacesOfFlatMapPt.xcworkspace`
+* Open `ManyFacesOfFlatMap.xcworkspace`
 * Build the package for _macOS_
 * Open the playground
diff --git a/0045-the-many-faces-of-flatmap-pt4/.gitignore b/0045-the-many-faces-of-flatmap-pt4/.gitignore
new file mode 100644
index 00000000..02c08753
--- /dev/null
+++ b/0045-the-many-faces-of-flatmap-pt4/.gitignore
@@ -0,0 +1,4 @@
+.DS_Store
+/.build
+/Packages
+/*.xcodeproj
diff --git a/0045-the-many-faces-of-flatmap-pt4/ManyFacesOfFlatMap.playground/Contents.swift b/0045-the-many-faces-of-flatmap-pt4/ManyFacesOfFlatMap.playground/Contents.swift
new file mode 100644
index 00000000..59d12fbe
--- /dev/null
+++ b/0045-the-many-faces-of-flatmap-pt4/ManyFacesOfFlatMap.playground/Contents.swift
@@ -0,0 +1,470 @@
+import Foundation
+
+func combos<A, B>(_ xs: [A], _ ys: [B]) -> [(A, B)] {
+  return xs.flatMap { x in
+    ys.map { y in
+      (x, y)
+    }
+  }
+}
+
+enum Result<A, E> {
+  case success(A)
+  case failure(E)
+
+  func map<B>(_ f: @escaping (A) -> B) -> Result<B, E> {
+    switch self {
+    case let .success(a):
+      return .success(f(a))
+    case let .failure(e):
+      return .failure(e)
+    }
+  }
+
+  public func flatMap<B>(_ transform: (A) -> Result<B, E>) -> Result<B, E> {
+    switch self {
+    case let .success(value):
+      return transform(value)
+    case let .failure(error):
+      return .failure(error)
+    }
+  }
+}
+
+import NonEmpty
+
+enum Validated<A, E> {
+  case valid(A)
+  case invalid(NonEmptyArray<E>)
+
+  func map<B>(_ f: @escaping (A) -> B) -> Validated<B, E> {
+    switch self {
+    case let .valid(a):
+      return .valid(f(a))
+    case let .invalid(e):
+      return .invalid(e)
+    }
+  }
+
+
+  public func flatMap<B>(_ transform: (A) -> Validated<B, E>) -> Validated<B, E> {
+    switch self {
+    case let .valid(value):
+      return transform(value)
+    case let .invalid(error):
+      return .invalid(error)
+    }
+  }
+}
+
+struct Func<A, B> {
+  let run: (A) -> B
+
+  func map<C>(_ f: @escaping (B) -> C) -> Func<A, C> {
+    return Func<A, C>(run: self.run >>> f)
+  }
+
+  func flatMap<C>(_ f: @escaping (B) -> Func<A, C>) -> Func<A, C> {
+    return Func<A, C> { a -> C in
+      f(self.run(a)).run(a)
+    }
+  }
+}
+
+let randomNumber = Func<Void, Int> {
+  let number = try! String(contentsOf: URL(string: "https://www.random.org/integers/?num=1&min=1&max=235866&col=1&base=10&format=plain&rnd=new")!)
+    .trimmingCharacters(in: .newlines)
+  return Int(number)!
+}
+
+let words = Func<Void, [String]> {
+  (try! String(contentsOf: URL(fileURLWithPath: "/usr/share/dict/words")))
+    .split(separator: "\n")
+    .map(String.init)
+}
+
+struct Parallel<A> {
+  let run: (@escaping (A) -> Void) -> Void
+
+  func map<B>(_ f: @escaping (A) -> B) -> Parallel<B> {
+    return Parallel<B> { callback in
+      self.run { a in callback(f(a)) }
+    }
+  }
+
+  func flatMap<B>(_ f: @escaping (A) -> Parallel<B>) -> Parallel<B> {
+    return Parallel<B> { callback in
+      self.run { a in
+        f(a).run(callback)
+      }
+    }
+  }
+}
+
+func delay(by duration: TimeInterval, line: UInt = #line) -> Parallel<Void> {
+  return Parallel { callback in
+    print("Delaying line \(line) by \(duration)")
+    DispatchQueue.main.asyncAfter(deadline: .now() + duration) {
+      print("Finished line \(line)")
+      callback(())
+    }
+  }
+}
+
+
+
+struct User: Codable {
+  let email: String
+  let id: Int
+  let name: String
+}
+
+//let user: User?
+//if let path = Bundle.main.path(forResource: "user", ofType:  "json"),
+//  case let url = URL.init(fileURLWithPath: path),
+//  let data = try? Data.init(contentsOf: url) {
+//
+//  user = try? JSONDecoder().decode(User.self, from: data)
+//} else {
+//  user = nil
+//}
+
+let newUser = Bundle.main.path(forResource: "user", ofType: "json")
+  .map(URL.init(fileURLWithPath:))
+  .flatMap { try? Data.init(contentsOf: $0) }
+  .flatMap { try? JSONDecoder().decode(User.self, from: $0) }
+
+
+struct Invoice: Codable {
+  let amountDue: Int
+  let amountPaid: Int
+  let closed: Bool
+  let id: Int
+}
+
+let invoices = Bundle.main.path(forResource: "invoices", ofType: "json")
+  .map(URL.init(fileURLWithPath:))
+  .flatMap { try? Data.init(contentsOf: $0) }
+  .flatMap { try? JSONDecoder().decode([Invoice].self, from: $0) }
+
+if let newUser = newUser, let invoices = invoices {
+  //
+}
+
+func zip<A, B>(_ a: A?, _ b: B?) -> (A, B)? {
+  if let a = a, let b = b { return (a, b) }
+  return nil
+}
+
+zip(newUser, invoices)
+
+struct UserEnvelope {
+  let user: User
+  let invoices: [Invoice]
+}
+
+func zip<A, B, C>(with f: @escaping (A, B) -> C) -> (A?, B?) -> C? {
+  return { zip($0, $1).map(f) }
+}
+
+struct SomeExpected: Error {}
+
+func requireSome<A>(_ a: A?) throws -> A {
+  guard let a = a else { throw SomeExpected() }
+  return a
+}
+
+do {
+  let path = try requireSome(Bundle.main.path(forResource: "user", ofType:  "json"))
+  let url = URL.init(fileURLWithPath: path)
+  let data = try Data.init(contentsOf: url)
+  let user = try JSONDecoder().decode(User.self, from: data)
+} catch {
+
+}
+
+
+extension Result where E == Swift.Error {
+  init(catching f: () throws -> A) {
+    do {
+      self = .success(try f())
+    } catch {
+      self = .failure(error)
+    }
+  }
+}
+
+extension Validated where E == Swift.Error {
+  init(catching f: () throws -> A) {
+    do {
+      self = .valid(try f())
+    } catch {
+      self = .invalid(NonEmptyArray(error))
+    }
+  }
+}
+
+
+
+func zip<A, B, E>(_ a: Result<A, E>, _ b: Result<B, E>) -> Result<(A, B), E> {
+  switch (a, b) {
+  case let (.success(a), .success(b)):
+    return .success((a, b))
+  case let (.failure(e), _):
+    return .failure(e)
+  case let (.success, .failure(e)):
+    return .failure(e)
+  }
+}
+
+
+func zip<A, B, C, E>(with f: @escaping (A, B) -> C) -> (Result<A, E>, Result<B, E>) -> Result<C, E> {
+  return { zip($0, $1).map(f) }
+}
+
+
+func zip<A, B, E>(_ a: Validated<A, E>, _ b: Validated<B, E>) -> Validated<(A, B), E> {
+  switch (a, b) {
+  case let (.valid(a), .valid(b)):
+    return .valid((a, b))
+  case let (.valid, .invalid(e)):
+    return .invalid(e)
+  case let (.invalid(e), .valid):
+    return .invalid(e)
+  case let (.invalid(e1), .invalid(e2)):
+    return .invalid(e1 + e2)
+  }
+}
+
+func zip<A, B, C, E>(with f: @escaping (A, B) -> C) -> (Validated<A, E>, Validated<B, E>) -> Validated<C, E> {
+  return { zip($0, $1).map(f) }
+}
+
+
+zip(with: UserEnvelope.init)(
+  Bundle.main.path(forResource: "user", ofType: "json")
+    .map(URL.init(fileURLWithPath:))
+    .flatMap { try? Data.init(contentsOf: $0) }
+    .flatMap { try? JSONDecoder().decode(User.self, from: $0) },
+
+  Bundle.main.path(forResource: "invoices", ofType: "json")
+    .map(URL.init(fileURLWithPath:))
+    .flatMap { try? Data.init(contentsOf: $0) }
+    .flatMap { try? JSONDecoder().decode([Invoice].self, from: $0) }
+)
+
+// failure(Swift.DecodingError.typeMismatch(Swift.Int, Swift.DecodingError.Context(codingPath: [CodingKeys(stringValue: "id", intValue: nil)], debugDescription: "Expected to decode Int but found a string/data instead.", underlyingError: nil)))
+zip(with: UserEnvelope.init)(
+  Result { try requireSome(Bundle.main.path(forResource: "user", ofType:  "json")) }
+    .map(URL.init(fileURLWithPath:))
+    .flatMap { url in Result { try Data.init(contentsOf: url) } }
+    .flatMap { data in Result { try JSONDecoder().decode(User.self, from: data) } },
+
+  Result { try requireSome(Bundle.main.path(forResource: "invoices", ofType:  "json")) }
+    .map(URL.init(fileURLWithPath:))
+    .flatMap { url in Result { try Data.init(contentsOf: url) } }
+    .flatMap { data in Result { try JSONDecoder().decode([Invoice].self, from: data) } }
+)
+
+// invalid(typeMismatch(Swift.Int, Swift.DecodingError.Context(codingPath: [CodingKeys(stringValue: "id", intValue: nil)], debugDescription: "Expected to decode Int but found a string/data instead.", underlyingError: nil))[Swift.DecodingError.typeMismatch(Swift.Int, Swift.DecodingError.Context(codingPath: [_JSONKey(stringValue: "Index 0", intValue: 0), CodingKeys(stringValue: "amountDue", intValue: nil)], debugDescription: "Expected to decode Int but found a string/data instead.", underlyingError: nil))])
+zip(with: UserEnvelope.init)(
+  Validated { try requireSome(Bundle.main.path(forResource: "user", ofType:  "json")) }
+    .map(URL.init(fileURLWithPath:))
+    .flatMap { url in Validated { try Data.init(contentsOf: url) } }
+    .flatMap { data in Validated { try JSONDecoder().decode(User.self, from: data) } },
+
+  Validated { try requireSome(Bundle.main.path(forResource: "invoices", ofType:  "json")) }
+    .map(URL.init(fileURLWithPath:))
+    .flatMap { url in Validated { try Data.init(contentsOf: url) } }
+    .flatMap { data in Validated { try JSONDecoder().decode([Invoice].self, from: data) } }
+)
+
+let lazyUser = Func { Bundle.main.path(forResource: "user", ofType:  "json")! }
+  .map(URL.init(fileURLWithPath:))
+  .flatMap { url in Func { try! Data.init(contentsOf: url) } }
+  .flatMap { data in Func { try! JSONDecoder().decode(User.self, from: data) } }
+
+lazyUser.run(())
+
+
+func zip<A, B, C>(_ ab: Func<A, B>, _ ac: Func<A, C>) -> Func<A, (B, C)> {
+  return Func<A, (B, C)> { a in
+    (ab.run(a), ac.run(a))
+  }
+}
+
+func zip<A, B, C, D>(with f: @escaping (B, C) -> D) -> (Func<A, B>, Func<A, C>) -> Func<A, D> {
+  return { zip($0, $1).map(f) }
+}
+
+zip(with: UserEnvelope.init)(
+  Func { Bundle.main.path(forResource: "user", ofType:  "json")! }
+    .map(URL.init(fileURLWithPath:))
+    .flatMap { url in Func { try! Data.init(contentsOf: url) } }
+    .flatMap { data in Func { try! JSONDecoder().decode(User.self, from: data) } },
+
+  Func { Bundle.main.path(forResource: "invoices", ofType:  "json")! }
+    .map(URL.init(fileURLWithPath:))
+    .flatMap { url in Func { try! Data.init(contentsOf: url) } }
+    .flatMap { data in Func { try! JSONDecoder().decode([Invoice].self, from: data) } }
+)
+
+extension Parallel {
+  init(_ work: @autoclosure @escaping () -> A) {
+    self = Parallel { callback in
+      DispatchQueue.global().async {
+        callback(work())
+      }
+    }
+  }
+}
+
+Parallel(Bundle.main.path(forResource: "user", ofType:  "json")!)
+  .map(URL.init(fileURLWithPath:))
+  .flatMap { url in Parallel(try! Data.init(contentsOf: url)) }
+  .flatMap { data in Parallel(try! JSONDecoder().decode(User.self, from: data)) }
+
+func zip<A, B>(_ pa: Parallel<A>, _ pb: Parallel<B>) -> Parallel<(A, B)> {
+  return Parallel<(A, B)> { callback in
+    var optionalA: A?
+    var optionalB: B?
+    pa.run { a in
+      optionalA = a
+      if let b = optionalB { callback((a, b)) }
+    }
+    pb.run { b in
+      optionalB = b
+      if let a = optionalA { callback((a, b)) }
+    }
+  }
+}
+
+func zip<A, B, C>(with f: @escaping (A, B) -> C) -> (Parallel<A>, Parallel<B>) -> Parallel<C> {
+  return { zip($0, $1).map(f) }
+}
+
+zip(with: UserEnvelope.init)(
+  Parallel(Bundle.main.path(forResource: "user", ofType:  "json")!)
+    .map(URL.init(fileURLWithPath:))
+    .flatMap { url in Parallel(try! Data.init(contentsOf: url)) }
+    .flatMap { data in Parallel(try! JSONDecoder().decode(User.self, from: data)) },
+
+  Parallel(Bundle.main.path(forResource: "invoices", ofType:  "json")!)
+    .map(URL.init(fileURLWithPath:))
+    .flatMap { url in Parallel(try! Data.init(contentsOf: url)) }
+    .flatMap { data in Parallel(try! JSONDecoder().decode([Invoice].self, from: data)) }
+  ).run { env in
+//    print(env)
+}
+
+//
+//do {
+//  let user = try JSONDecoder().decode(
+//    User.self,
+//    from: Data.init(
+//      contentsOf: URL.init(
+//        fileURLWithPath: requireSome(
+//          Bundle.main.path(
+//            forResource: "user",
+//            ofType:  "json"
+//          )
+//        )
+//      )
+//    )
+//  )
+//} catch {
+//
+//}
+
+
+//extension Sequence {
+//  public func flatMap<ElementOfResult>(_ transform: (Element) throws -> ElementOfResult?) rethrows -> [ElementOfResult]
+//}
+
+// flatMap: ((A) -> B?) -> ((F<A>) -> F<B>)
+
+
+//func fromThrowing<A, B>(_ f: @escaping (A) throws -> B) -> (A) -> Result<B, Swift.Error> {
+//  return { a in
+//    do {
+//      return .success(try f(a))
+//    } catch let error {
+//      return .failure(error)
+//    }
+//  }
+//}
+//
+//func toThrowing<A, B>(_ f: @escaping (A) -> Result<B, Swift.Error>) -> ((A) throws -> B) {
+//  return { a in
+//    switch f(a) {
+//    case let .success(value):
+//      return value
+//    case let .failure(error):
+//      throw error
+//    }
+//  }
+//}
+//
+//extension Result {
+//  func map<B>(_ f: @escaping (A) -> Result<B, Swift.Error>) -> Result<B, Swift.Error> {
+//    fatalError()
+//  }
+//
+//  func flatMap<B>(_ f: @escaping (A) -> Result<Result<B, E>, Swift.Error>) -> Result<B, Swift.Error> {
+//    fatalError()
+//  }
+//}
+
+//extension Func /* <A, B> */ {
+//  func flatMap<C>(_ f: @escaping (A) -> Func<C, B>) -> Func<C, B> {
+//
+//  }
+//}
+
+import XCTest
+struct Diffing<Value> {
+  let toData: (Value) -> Data
+  let fromData: (Data) -> Value
+  let diff: (Value, Value) -> (String, [XCTAttachment])?
+
+  func flatMap<NewValue>(_ f: @escaping (Value) -> Diffing<NewValue>) -> Diffing<NewValue> {
+    fatalError("Not possible to implement.")
+  }
+}
+
+struct Snapshotting<Value, Format> {
+  var pathExtension: String?
+  let diffing: Diffing<Format>
+  let snapshot: (Value) -> Format
+
+  func flatMap<NewValue>(_ f: @escaping (Value) -> Snapshotting<NewValue, Format>) -> Snapshotting<NewValue, Format> {
+    fatalError("Not possible to implement.")
+  }
+
+  func flatMap<NewFormat>(_ f: @escaping (Format) -> Snapshotting<Value, NewFormat>) -> Snapshotting<Value, NewFormat> {
+    fatalError("Not possible to implement.")
+  }
+}
+
+
+extension Parallel {
+  func then<B>(_ f: @escaping (A) -> Parallel<B>) -> Parallel<B> {
+    return self.flatMap(f)
+  }
+}
+
+extension Parallel {
+  func then<B>(_ f: @escaping (A) -> B) -> Parallel<B> {
+    return self.map(f)
+  }
+}
+
+Parallel(Bundle.main.path(forResource: "user", ofType:  "json")!)
+  .then(URL.init(fileURLWithPath:))
+  .then { url in Parallel(try! Data.init(contentsOf: url)) }
+  .then { data in Parallel(try! JSONDecoder().decode(User.self, from: data)) }
+
+Parallel(Bundle.main.path(forResource: "user", ofType:  "json")!)
+  .map(URL.init(fileURLWithPath:))
+  .flatMap { url in Parallel(try! Data.init(contentsOf: url)) }
+  .flatMap { data in Parallel(try! JSONDecoder().decode(User.self, from: data)) }
diff --git a/0045-the-many-faces-of-flatmap-pt4/ManyFacesOfFlatMap.playground/Resources/invoices.json b/0045-the-many-faces-of-flatmap-pt4/ManyFacesOfFlatMap.playground/Resources/invoices.json
new file mode 100644
index 00000000..8c0af97b
--- /dev/null
+++ b/0045-the-many-faces-of-flatmap-pt4/ManyFacesOfFlatMap.playground/Resources/invoices.json
@@ -0,0 +1,14 @@
+[
+  {
+    "amountPaid": 1000,
+    "amountDue": 0,
+    "closed": true,
+    "id": 1
+  },
+  {
+    "amountPaid": 500,
+    "amountDue": 500,
+    "closed": false,
+    "id": 2
+  }
+]
diff --git a/0045-the-many-faces-of-flatmap-pt4/ManyFacesOfFlatMap.playground/Resources/user.json b/0045-the-many-faces-of-flatmap-pt4/ManyFacesOfFlatMap.playground/Resources/user.json
new file mode 100644
index 00000000..ae6fc81d
--- /dev/null
+++ b/0045-the-many-faces-of-flatmap-pt4/ManyFacesOfFlatMap.playground/Resources/user.json
@@ -0,0 +1,5 @@
+{
+  "email": "blob@pointfree.co",
+  "id": 42,
+  "name": "Blob"
+}
diff --git a/0045-the-many-faces-of-flatmap-pt4/ManyFacesOfFlatMap.playground/Sources/Util.swift b/0045-the-many-faces-of-flatmap-pt4/ManyFacesOfFlatMap.playground/Sources/Util.swift
new file mode 100644
index 00000000..e8ec0129
--- /dev/null
+++ b/0045-the-many-faces-of-flatmap-pt4/ManyFacesOfFlatMap.playground/Sources/Util.swift
@@ -0,0 +1,17 @@
+precedencegroup EffectfulComposition {
+  associativity: left
+  higherThan: AssignmentPrecedence
+}
+
+infix operator >=>: EffectfulComposition
+
+precedencegroup ForwardComposition {
+  associativity: left
+  higherThan: EffectfulComposition
+}
+
+infix operator >>>: ForwardComposition
+
+public func >>> <A, B, C>(f: @escaping (A) -> B, g: @escaping (B) -> C) -> (A) -> C {
+  return { a in g(f(a)) }
+}
diff --git a/0045-the-many-faces-of-flatmap-pt4/ManyFacesOfFlatMap.playground/contents.xcplayground b/0045-the-many-faces-of-flatmap-pt4/ManyFacesOfFlatMap.playground/contents.xcplayground
new file mode 100644
index 00000000..a93d4844
--- /dev/null
+++ b/0045-the-many-faces-of-flatmap-pt4/ManyFacesOfFlatMap.playground/contents.xcplayground
@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<playground version='5.0' target-platform='macos' executeOnSourceChanges='false'>
+    <timeline fileName='timeline.xctimeline'/>
+</playground>
\ No newline at end of file
diff --git a/0045-the-many-faces-of-flatmap-pt4/ManyFacesOfFlatMap.xcworkspace/contents.xcworkspacedata b/0045-the-many-faces-of-flatmap-pt4/ManyFacesOfFlatMap.xcworkspace/contents.xcworkspacedata
new file mode 100644
index 00000000..cb4198ae
--- /dev/null
+++ b/0045-the-many-faces-of-flatmap-pt4/ManyFacesOfFlatMap.xcworkspace/contents.xcworkspacedata
@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Workspace
+   version = "1.0">
+   <FileRef
+      location = "group:ManyFacesOfFlatMap.playground">
+   </FileRef>
+   <FileRef
+      location = "group:ManyFacesOfFlatMap.xcodeproj">
+   </FileRef>
+</Workspace>
diff --git a/0045-the-many-faces-of-flatmap-pt4/ManyFacesOfFlatMap.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist b/0045-the-many-faces-of-flatmap-pt4/ManyFacesOfFlatMap.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist
new file mode 100644
index 00000000..18d98100
--- /dev/null
+++ b/0045-the-many-faces-of-flatmap-pt4/ManyFacesOfFlatMap.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist
@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>IDEDidComputeMac32BitWarning</key>
+	<true/>
+</dict>
+</plist>
diff --git a/0045-the-many-faces-of-flatmap-pt4/ManyFacesOfFlatMap.xcworkspace/xcshareddata/WorkspaceSettings.xcsettings b/0045-the-many-faces-of-flatmap-pt4/ManyFacesOfFlatMap.xcworkspace/xcshareddata/WorkspaceSettings.xcsettings
new file mode 100644
index 00000000..a72dc2b4
--- /dev/null
+++ b/0045-the-many-faces-of-flatmap-pt4/ManyFacesOfFlatMap.xcworkspace/xcshareddata/WorkspaceSettings.xcsettings
@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+    <key>IDEWorkspaceSharedSettings_AutocreateContextsIfNeeded</key>
+    <false/>
+</dict>
+</plist>
\ No newline at end of file
diff --git a/0045-the-many-faces-of-flatmap-pt4/Package.resolved b/0045-the-many-faces-of-flatmap-pt4/Package.resolved
new file mode 100644
index 00000000..933b69f4
--- /dev/null
+++ b/0045-the-many-faces-of-flatmap-pt4/Package.resolved
@@ -0,0 +1,16 @@
+{
+  "object": {
+    "pins": [
+      {
+        "package": "NonEmpty",
+        "repositoryURL": "https://github.com/pointfreeco/swift-nonempty.git",
+        "state": {
+          "branch": null,
+          "revision": "bcf639e8ec6c20b6b7b28ed9bfa0fe83450c3248",
+          "version": "0.1.2"
+        }
+      }
+    ]
+  },
+  "version": 1
+}
diff --git a/0045-the-many-faces-of-flatmap-pt4/Package.swift b/0045-the-many-faces-of-flatmap-pt4/Package.swift
new file mode 100644
index 00000000..156e9c16
--- /dev/null
+++ b/0045-the-many-faces-of-flatmap-pt4/Package.swift
@@ -0,0 +1,24 @@
+// swift-tools-version:4.2
+// The swift-tools-version declares the minimum version of Swift required to build this package.
+
+import PackageDescription
+
+let package = Package(
+    name: "ManyFacesOfFlatMap",
+    products: [
+        // Products define the executables and libraries produced by a package, and make them visible to other packages.
+        .library(
+            name: "ManyFacesOfFlatMap",
+            targets: ["ManyFacesOfFlatMap"]),
+    ],
+    dependencies: [
+        .package(url: "https://github.com/pointfreeco/swift-nonempty.git", from: "0.1.2")
+    ],
+    targets: [
+        // Targets are the basic building blocks of a package. A target can define a module or a test suite.
+        // Targets can depend on other targets in this package, and on products in packages which this package depends on.
+        .target(
+            name: "ManyFacesOfFlatMap",
+            dependencies: ["NonEmpty"])
+    ]
+)
diff --git a/0045-the-many-faces-of-flatmap-pt4/README.md b/0045-the-many-faces-of-flatmap-pt4/README.md
new file mode 100644
index 00000000..aae45fa7
--- /dev/null
+++ b/0045-the-many-faces-of-flatmap-pt4/README.md
@@ -0,0 +1,14 @@
+## [Point-Free](https://www.pointfree.co)
+
+> #### This directory contains code from Point-Free Episode: [The Many Faces of Flat-Map: Part 4](https://www.pointfree.co/episodes/ep45-the-many-faces-of-flat-map-part-4)
+>
+> Continuing our 3-part answer to the all-important question "what's the point?", we show that the definitions of `map`, `zip` and `flatMap` are precise and concisely describe their purpose. Knowing this we can strengthen our APIs by not smudging their definitions when convenient.
+
+### Getting Started
+
+* Clone repo
+* `cd` into this directory
+* Run `swift package generate-xcodeproj`
+* Open `ManyFacesOfFlatMap.xcworkspace`
+* Build the package for _macOS_
+* Open the playground
diff --git a/0045-the-many-faces-of-flatmap-pt4/Sources/ManyFacesOfFlatMap/ManyFacesOfFlatMap.swift b/0045-the-many-faces-of-flatmap-pt4/Sources/ManyFacesOfFlatMap/ManyFacesOfFlatMap.swift
new file mode 100644
index 00000000..8fcf9749
--- /dev/null
+++ b/0045-the-many-faces-of-flatmap-pt4/Sources/ManyFacesOfFlatMap/ManyFacesOfFlatMap.swift
@@ -0,0 +1,2 @@
+
+let x = 1
diff --git a/0046-the-many-faces-of-flatmap-pt5/.gitignore b/0046-the-many-faces-of-flatmap-pt5/.gitignore
new file mode 100644
index 00000000..02c08753
--- /dev/null
+++ b/0046-the-many-faces-of-flatmap-pt5/.gitignore
@@ -0,0 +1,4 @@
+.DS_Store
+/.build
+/Packages
+/*.xcodeproj
diff --git a/0046-the-many-faces-of-flatmap-pt5/ManyFacesOfFlatMap.playground/Contents.swift b/0046-the-many-faces-of-flatmap-pt5/ManyFacesOfFlatMap.playground/Contents.swift
new file mode 100644
index 00000000..b63079f2
--- /dev/null
+++ b/0046-the-many-faces-of-flatmap-pt5/ManyFacesOfFlatMap.playground/Contents.swift
@@ -0,0 +1,682 @@
+import Foundation
+
+func combos<A, B>(_ xs: [A], _ ys: [B]) -> [(A, B)] {
+  return xs.flatMap { x in
+    ys.map { y in
+      (x, y)
+    }
+  }
+}
+
+enum Result<A, E> {
+  case success(A)
+  case failure(E)
+
+  func map<B>(_ f: @escaping (A) -> B) -> Result<B, E> {
+    switch self {
+    case let .success(a):
+      return .success(f(a))
+    case let .failure(e):
+      return .failure(e)
+    }
+  }
+
+  public func flatMap<B>(_ transform: (A) -> Result<B, E>) -> Result<B, E> {
+    switch self {
+    case let .success(value):
+      return transform(value)
+    case let .failure(error):
+      return .failure(error)
+    }
+  }
+}
+
+import NonEmpty
+
+enum Validated<A, E> {
+  case valid(A)
+  case invalid(NonEmptyArray<E>)
+
+  func map<B>(_ f: @escaping (A) -> B) -> Validated<B, E> {
+    switch self {
+    case let .valid(a):
+      return .valid(f(a))
+    case let .invalid(e):
+      return .invalid(e)
+    }
+  }
+
+
+  public func flatMap<B>(_ transform: (A) -> Validated<B, E>) -> Validated<B, E> {
+    switch self {
+    case let .valid(value):
+      return transform(value)
+    case let .invalid(error):
+      return .invalid(error)
+    }
+  }
+}
+
+struct Func<A, B> {
+  let run: (A) -> B
+
+  func map<C>(_ f: @escaping (B) -> C) -> Func<A, C> {
+    return Func<A, C>(run: self.run >>> f)
+  }
+
+  func flatMap<C>(_ f: @escaping (B) -> Func<A, C>) -> Func<A, C> {
+    return Func<A, C> { a -> C in
+      f(self.run(a)).run(a)
+    }
+  }
+}
+
+let randomNumber = Func<Void, Int> {
+  let number = try! String(contentsOf: URL(string: "https://www.random.org/integers/?num=1&min=1&max=235866&col=1&base=10&format=plain&rnd=new")!)
+    .trimmingCharacters(in: .newlines)
+  return Int(number)!
+}
+
+let words = Func<Void, [String]> {
+  (try! String(contentsOf: URL(fileURLWithPath: "/usr/share/dict/words")))
+    .split(separator: "\n")
+    .map(String.init)
+}
+
+struct Parallel<A> {
+  let run: (@escaping (A) -> Void) -> Void
+
+  func map<B>(_ f: @escaping (A) -> B) -> Parallel<B> {
+    return Parallel<B> { callback in
+      self.run { a in callback(f(a)) }
+    }
+  }
+
+  func flatMap<B>(_ f: @escaping (A) -> Parallel<B>) -> Parallel<B> {
+    return Parallel<B> { callback in
+      self.run { a in
+        f(a).run(callback)
+      }
+    }
+  }
+}
+
+func delay(by duration: TimeInterval, line: UInt = #line) -> Parallel<Void> {
+  return Parallel { callback in
+    print("Delaying line \(line) by \(duration)")
+    DispatchQueue.main.asyncAfter(deadline: .now() + duration) {
+      print("Finished line \(line)")
+      callback(())
+    }
+  }
+}
+
+
+
+struct User: Codable {
+  let email: String
+  let id: Int
+  let name: String
+}
+
+//let user: User?
+//if let path = Bundle.main.path(forResource: "user", ofType:  "json"),
+//  case let url = URL.init(fileURLWithPath: path),
+//  let data = try? Data.init(contentsOf: url) {
+//
+//  user = try? JSONDecoder().decode(User.self, from: data)
+//} else {
+//  user = nil
+//}
+
+let newUser = Bundle.main.path(forResource: "user", ofType: "json")
+  .map(URL.init(fileURLWithPath:))
+  .flatMap { try? Data.init(contentsOf: $0) }
+  .flatMap { try? JSONDecoder().decode(User.self, from: $0) }
+
+
+struct Invoice: Codable {
+  let amountDue: Int
+  let amountPaid: Int
+  let closed: Bool
+  let id: Int
+}
+
+let invoices = Bundle.main.path(forResource: "invoices", ofType: "json")
+  .map(URL.init(fileURLWithPath:))
+  .flatMap { try? Data.init(contentsOf: $0) }
+  .flatMap { try? JSONDecoder().decode([Invoice].self, from: $0) }
+
+if let newUser = newUser, let invoices = invoices {
+  //
+}
+
+func zip<A, B>(_ a: A?, _ b: B?) -> (A, B)? {
+  if let a = a, let b = b { return (a, b) }
+  return nil
+}
+
+zip(newUser, invoices)
+
+struct UserEnvelope {
+  let user: User
+  let invoices: [Invoice]
+}
+
+func zip<A, B, C>(with f: @escaping (A, B) -> C) -> (A?, B?) -> C? {
+  return { zip($0, $1).map(f) }
+}
+
+struct SomeExpected: Error {}
+
+func requireSome<A>(_ a: A?) throws -> A {
+  guard let a = a else { throw SomeExpected() }
+  return a
+}
+
+do {
+  let path = try requireSome(Bundle.main.path(forResource: "user", ofType:  "json"))
+  let url = URL.init(fileURLWithPath: path)
+  let data = try Data.init(contentsOf: url)
+  let user = try JSONDecoder().decode(User.self, from: data)
+} catch {
+
+}
+
+
+extension Result where E == Swift.Error {
+  init(catching f: () throws -> A) {
+    do {
+      self = .success(try f())
+    } catch {
+      self = .failure(error)
+    }
+  }
+}
+
+extension Validated where E == Swift.Error {
+  init(catching f: () throws -> A) {
+    do {
+      self = .valid(try f())
+    } catch {
+      self = .invalid(NonEmptyArray(error))
+    }
+  }
+}
+
+
+
+func zip<A, B, E>(_ a: Result<A, E>, _ b: Result<B, E>) -> Result<(A, B), E> {
+  switch (a, b) {
+  case let (.success(a), .success(b)):
+    return .success((a, b))
+  case let (.failure(e), _):
+    return .failure(e)
+  case let (.success, .failure(e)):
+    return .failure(e)
+  }
+}
+
+
+func zip<A, B, C, E>(with f: @escaping (A, B) -> C) -> (Result<A, E>, Result<B, E>) -> Result<C, E> {
+  return { zip($0, $1).map(f) }
+}
+
+
+func zip<A, B, E>(_ a: Validated<A, E>, _ b: Validated<B, E>) -> Validated<(A, B), E> {
+  switch (a, b) {
+  case let (.valid(a), .valid(b)):
+    return .valid((a, b))
+  case let (.valid, .invalid(e)):
+    return .invalid(e)
+  case let (.invalid(e), .valid):
+    return .invalid(e)
+  case let (.invalid(e1), .invalid(e2)):
+    return .invalid(e1 + e2)
+  }
+}
+
+func zip<A, B, C, E>(with f: @escaping (A, B) -> C) -> (Validated<A, E>, Validated<B, E>) -> Validated<C, E> {
+  return { zip($0, $1).map(f) }
+}
+
+
+zip(with: UserEnvelope.init)(
+  Bundle.main.path(forResource: "user", ofType: "json")
+    .map(URL.init(fileURLWithPath:))
+    .flatMap { try? Data.init(contentsOf: $0) }
+    .flatMap { try? JSONDecoder().decode(User.self, from: $0) },
+
+  Bundle.main.path(forResource: "invoices", ofType: "json")
+    .map(URL.init(fileURLWithPath:))
+    .flatMap { try? Data.init(contentsOf: $0) }
+    .flatMap { try? JSONDecoder().decode([Invoice].self, from: $0) }
+)
+
+// failure(Swift.DecodingError.typeMismatch(Swift.Int, Swift.DecodingError.Context(codingPath: [CodingKeys(stringValue: "id", intValue: nil)], debugDescription: "Expected to decode Int but found a string/data instead.", underlyingError: nil)))
+zip(with: UserEnvelope.init)(
+  Result { try requireSome(Bundle.main.path(forResource: "user", ofType:  "json")) }
+    .map(URL.init(fileURLWithPath:))
+    .flatMap { url in Result { try Data.init(contentsOf: url) } }
+    .flatMap { data in Result { try JSONDecoder().decode(User.self, from: data) } },
+
+  Result { try requireSome(Bundle.main.path(forResource: "invoices", ofType:  "json")) }
+    .map(URL.init(fileURLWithPath:))
+    .flatMap { url in Result { try Data.init(contentsOf: url) } }
+    .flatMap { data in Result { try JSONDecoder().decode([Invoice].self, from: data) } }
+)
+
+// invalid(typeMismatch(Swift.Int, Swift.DecodingError.Context(codingPath: [CodingKeys(stringValue: "id", intValue: nil)], debugDescription: "Expected to decode Int but found a string/data instead.", underlyingError: nil))[Swift.DecodingError.typeMismatch(Swift.Int, Swift.DecodingError.Context(codingPath: [_JSONKey(stringValue: "Index 0", intValue: 0), CodingKeys(stringValue: "amountDue", intValue: nil)], debugDescription: "Expected to decode Int but found a string/data instead.", underlyingError: nil))])
+zip(with: UserEnvelope.init)(
+  Validated { try requireSome(Bundle.main.path(forResource: "user", ofType:  "json")) }
+    .map(URL.init(fileURLWithPath:))
+    .flatMap { url in Validated { try Data.init(contentsOf: url) } }
+    .flatMap { data in Validated { try JSONDecoder().decode(User.self, from: data) } },
+
+  Validated { try requireSome(Bundle.main.path(forResource: "invoices", ofType:  "json")) }
+    .map(URL.init(fileURLWithPath:))
+    .flatMap { url in Validated { try Data.init(contentsOf: url) } }
+    .flatMap { data in Validated { try JSONDecoder().decode([Invoice].self, from: data) } }
+)
+
+let lazyUser = Func { Bundle.main.path(forResource: "user", ofType:  "json")! }
+  .map(URL.init(fileURLWithPath:))
+  .flatMap { url in Func { try! Data.init(contentsOf: url) } }
+  .flatMap { data in Func { try! JSONDecoder().decode(User.self, from: data) } }
+
+lazyUser.run(())
+
+
+func zip<A, B, C>(_ ab: Func<A, B>, _ ac: Func<A, C>) -> Func<A, (B, C)> {
+  return Func<A, (B, C)> { a in
+    (ab.run(a), ac.run(a))
+  }
+}
+
+func zip<A, B, C, D>(with f: @escaping (B, C) -> D) -> (Func<A, B>, Func<A, C>) -> Func<A, D> {
+  return { zip($0, $1).map(f) }
+}
+
+zip(with: UserEnvelope.init)(
+  Func { Bundle.main.path(forResource: "user", ofType:  "json")! }
+    .map(URL.init(fileURLWithPath:))
+    .flatMap { url in Func { try! Data.init(contentsOf: url) } }
+    .flatMap { data in Func { try! JSONDecoder().decode(User.self, from: data) } },
+
+  Func { Bundle.main.path(forResource: "invoices", ofType:  "json")! }
+    .map(URL.init(fileURLWithPath:))
+    .flatMap { url in Func { try! Data.init(contentsOf: url) } }
+    .flatMap { data in Func { try! JSONDecoder().decode([Invoice].self, from: data) } }
+)
+
+extension Parallel {
+  init(_ work: @autoclosure @escaping () -> A) {
+    self = Parallel { callback in
+      DispatchQueue.global().async {
+        callback(work())
+      }
+    }
+  }
+}
+
+Parallel(Bundle.main.path(forResource: "user", ofType:  "json")!)
+  .map(URL.init(fileURLWithPath:))
+  .flatMap { url in Parallel(try! Data.init(contentsOf: url)) }
+  .flatMap { data in Parallel(try! JSONDecoder().decode(User.self, from: data)) }
+
+func zip<A, B>(_ pa: Parallel<A>, _ pb: Parallel<B>) -> Parallel<(A, B)> {
+  return Parallel<(A, B)> { callback in
+    var optionalA: A?
+    var optionalB: B?
+    pa.run { a in
+      optionalA = a
+      if let b = optionalB { callback((a, b)) }
+    }
+    pb.run { b in
+      optionalB = b
+      if let a = optionalA { callback((a, b)) }
+    }
+  }
+}
+
+func zip<A, B, C>(with f: @escaping (A, B) -> C) -> (Parallel<A>, Parallel<B>) -> Parallel<C> {
+  return { zip($0, $1).map(f) }
+}
+
+zip(with: UserEnvelope.init)(
+  Parallel(Bundle.main.path(forResource: "user", ofType:  "json")!)
+    .map(URL.init(fileURLWithPath:))
+    .flatMap { url in Parallel(try! Data.init(contentsOf: url)) }
+    .flatMap { data in Parallel(try! JSONDecoder().decode(User.self, from: data)) },
+
+  Parallel(Bundle.main.path(forResource: "invoices", ofType:  "json")!)
+    .map(URL.init(fileURLWithPath:))
+    .flatMap { url in Parallel(try! Data.init(contentsOf: url)) }
+    .flatMap { data in Parallel(try! JSONDecoder().decode([Invoice].self, from: data)) }
+  ).run { env in
+//    print(env)
+}
+
+//
+//do {
+//  let user = try JSONDecoder().decode(
+//    User.self,
+//    from: Data.init(
+//      contentsOf: URL.init(
+//        fileURLWithPath: requireSome(
+//          Bundle.main.path(
+//            forResource: "user",
+//            ofType:  "json"
+//          )
+//        )
+//      )
+//    )
+//  )
+//} catch {
+//
+//}
+
+
+//extension Sequence {
+//  public func flatMap<ElementOfResult>(_ transform: (Element) throws -> ElementOfResult?) rethrows -> [ElementOfResult]
+//}
+
+// flatMap: ((A) -> B?) -> ((F<A>) -> F<B>)
+
+
+//func fromThrowing<A, B>(_ f: @escaping (A) throws -> B) -> (A) -> Result<B, Swift.Error> {
+//  return { a in
+//    do {
+//      return .success(try f(a))
+//    } catch let error {
+//      return .failure(error)
+//    }
+//  }
+//}
+//
+//func toThrowing<A, B>(_ f: @escaping (A) -> Result<B, Swift.Error>) -> ((A) throws -> B) {
+//  return { a in
+//    switch f(a) {
+//    case let .success(value):
+//      return value
+//    case let .failure(error):
+//      throw error
+//    }
+//  }
+//}
+//
+//extension Result {
+//  func map<B>(_ f: @escaping (A) -> Result<B, Swift.Error>) -> Result<B, Swift.Error> {
+//    fatalError()
+//  }
+//
+//  func flatMap<B>(_ f: @escaping (A) -> Result<Result<B, E>, Swift.Error>) -> Result<B, Swift.Error> {
+//    fatalError()
+//  }
+//}
+
+//extension Func /* <A, B> */ {
+//  func flatMap<C>(_ f: @escaping (A) -> Func<C, B>) -> Func<C, B> {
+//
+//  }
+//}
+
+import XCTest
+struct Diffing<Value> {
+  let toData: (Value) -> Data
+  let fromData: (Data) -> Value
+  let diff: (Value, Value) -> (String, [XCTAttachment])?
+
+  func flatMap<NewValue>(_ f: @escaping (Value) -> Diffing<NewValue>) -> Diffing<NewValue> {
+    fatalError("Not possible to implement.")
+  }
+}
+
+struct Snapshotting<Value, Format> {
+  var pathExtension: String?
+  let diffing: Diffing<Format>
+  let snapshot: (Value) -> Format
+
+  func flatMap<NewValue>(_ f: @escaping (Value) -> Snapshotting<NewValue, Format>) -> Snapshotting<NewValue, Format> {
+    fatalError("Not possible to implement.")
+  }
+
+  func flatMap<NewFormat>(_ f: @escaping (Format) -> Snapshotting<Value, NewFormat>) -> Snapshotting<Value, NewFormat> {
+    fatalError("Not possible to implement.")
+  }
+}
+
+
+extension Parallel {
+  func then<B>(_ f: @escaping (A) -> Parallel<B>) -> Parallel<B> {
+    return self.flatMap(f)
+  }
+}
+
+extension Parallel {
+  func then<B>(_ f: @escaping (A) -> B) -> Parallel<B> {
+    return self.map(f)
+  }
+}
+
+Parallel(Bundle.main.path(forResource: "user", ofType:  "json")!)
+  .then(URL.init(fileURLWithPath:))
+  .then { url in Parallel(try! Data.init(contentsOf: url)) }
+  .then { data in Parallel(try! JSONDecoder().decode(User.self, from: data)) }
+
+Parallel(Bundle.main.path(forResource: "user", ofType:  "json")!)
+  .map(URL.init(fileURLWithPath:))
+  .flatMap { url in Parallel(try! Data.init(contentsOf: url)) }
+  .flatMap { data in Parallel(try! JSONDecoder().decode(User.self, from: data)) }
+
+
+
+
+func pipe<A, B, C>(
+  _ lhs: @escaping (A) -> B,
+  _ rhs: @escaping (B) -> C
+  ) -> (A) -> C {
+  return lhs >>> rhs
+}
+
+pipe({ $0 + 1 }, { $0 * $0 })
+pipe({ $0 + 1 }, String.init)
+
+let f = { $0 + 1 }
+  >>> { $0 * $0 }
+  >>> { $0 + 1 }
+
+
+//_ = { try? Data.init(contentsOf: $0) }
+//  >>> { try? JSONDecoder().decode(User.self, from: $0) }
+
+func chain<A, B, C>(
+  _ lhs: @escaping (A) -> B?,
+  _ rhs: @escaping (B) -> C?
+  ) -> (A) -> C? {
+  return { a in
+    lhs(a).flatMap(rhs)
+  }
+}
+
+func >=> <A, B, C>(
+  _ lhs: @escaping (A) -> B?,
+  _ rhs: @escaping (B) -> C?
+  ) -> (A) -> C? {
+  return { a in
+    lhs(a).flatMap(rhs)
+  }
+}
+
+
+pipe(
+  URL.init(fileURLWithPath:),
+  chain(
+    { try? Data.init(contentsOf: $0) },
+    { try? JSONDecoder().decode(User.self, from: $0) }
+  )
+)
+
+let loadUser = URL.init(fileURLWithPath:)
+  >>> { try? Data.init(contentsOf: $0) }
+  >=> { try? JSONDecoder().decode(User.self, from: $0) }
+
+Bundle.main.path(forResource: "user", ofType: "json")
+  .map(URL.init(fileURLWithPath:))
+  .flatMap { try? Data.init(contentsOf: $0) }
+  .flatMap { try? JSONDecoder().decode(User.self, from: $0) }
+
+Bundle.main.path(forResource: "user", ofType: "json")
+  .flatMap(loadUser)
+
+
+// Parallel<Result<A, E>>
+
+func map<A, B, E>(
+  _ f: @escaping (A) -> B
+  ) -> (Parallel<Result<A, E>>) -> Parallel<Result<B, E>> {
+
+  return { parallelResultA in
+    parallelResultA.map { resultA in
+      resultA.map { a in
+        f(a)
+      }
+    }
+  }
+}
+
+func zip<A, B, E>(
+  _ lhs: Parallel<Result<A, E>>,
+  _ rhs: Parallel<Result<B, E>>
+  ) -> Parallel<Result<(A, B), E>> {
+
+  return zip(with: zip)(lhs, rhs)
+
+//  return zip(lhs, rhs).map { resultA, resultB in
+//    zip(resultA, resultB)
+//  }
+}
+
+func flatMap<A, B, E>(
+  _ f: @escaping (A) -> Parallel<Result<B, E>>
+  ) -> (Parallel<Result<A, E>>) -> Parallel<Result<B, E>> {
+
+  return { parallelResultA in
+    parallelResultA.flatMap { resultA in
+      Parallel<Result<B, E>> { callback in
+        switch resultA {
+        case let .success(a):
+          f(a).run { resultB in callback(resultB) }
+        case let .failure(error):
+          callback(.failure(error))
+        }
+      }
+    }
+  }
+}
+
+
+extension Optional {
+  func newMap<NewWrapped>(_ f: (Wrapped) -> NewWrapped) -> NewWrapped? {
+    return self.flatMap { Optional<NewWrapped>.some(f($0)) }
+  }
+}
+
+extension Array {
+  func newMap<NewElement>(_ f: (Element) -> NewElement) -> [NewElement] {
+    return self.flatMap { [f($0)] }
+  }
+}
+
+extension Result {
+  func newMap<B>(_ f: (A) -> B) -> Result<B, E> {
+    return self.flatMap { .success(f($0)) }
+  }
+}
+
+extension Validated {
+  func newMap<B>(_ f: (A) -> B) -> Validated<B, E> {
+    return self.flatMap { .valid(f($0)) }
+  }
+}
+
+extension Func {
+  func newMap<C>(_ f: @escaping (B) -> C) -> Func<A, C> {
+    return self.flatMap { b in Func<A, C> { _ in f(b) } }
+  }
+}
+
+extension Parallel {
+  func newMap<B>(_ f: @escaping (A) -> B) -> Parallel<B> {
+    return self.flatMap { a in Parallel<B> { callback in callback(f(a)) } }
+  }
+}
+
+func newZip<A, B>(_ a: A?, _ b: B?) -> (A, B)? {
+  return a.flatMap { a in
+    b.flatMap { b in
+      Optional.some((a, b))
+    }
+  }
+}
+
+func newZip<A, B>(_ a: [A], _ b: [B]) -> [(A, B)] {
+  return a.flatMap { a in
+    b.flatMap { b in
+      [(a, b)]
+    }
+  }
+}
+
+newZip(["a", "b"], [1, 2])
+
+func newZip<A, B, E>(_ a: Result<A, E>, _ b: Result<B, E>) -> Result<(A, B), E> {
+  return a.flatMap { a in
+    b.flatMap { b in
+      Result.success((a, b))
+    }
+  }
+}
+
+func newZip<A, B, E>(_ a: Validated<A, E>, _ b: Validated<B, E>) -> Validated<(A, B), E> {
+  return a.flatMap { a in
+    b.flatMap { b in
+      Validated.valid((a, b))
+    }
+  }
+}
+
+newZip(Validated<Int, String>.valid(1), .valid("Two"))
+
+
+newZip(Validated<Int, String>.invalid(NonEmptyArray("Something went wrong.")), .valid(2))
+
+newZip(
+  Validated<Int, String>.invalid(NonEmptyArray("Something went wrong.")),
+  Validated<Int, String>.invalid(NonEmptyArray("Something else went wrong."))
+)
+
+func newZip<A, B, C>(_ a: Func<A, B>, _ b: Func<A, C>) -> Func<A, (B, C)> {
+  return a.flatMap { a in
+    b.flatMap { b in
+      Func { _ in (a, b) }
+    }
+  }
+}
+
+func newZip<A, B>(_ a: Parallel<A>, _ b: Parallel<B>) -> Parallel<(A, B)> {
+  return a.flatMap { a in
+    b.flatMap { b in
+      Parallel { callback in callback((a, b)) }
+    }
+  }
+}
+
+newZip(delay(by: 2).map { 2 }, delay(by: 3).map { 3 }).run {
+  print($0)
+}
+
+
+
+
+
diff --git a/0046-the-many-faces-of-flatmap-pt5/ManyFacesOfFlatMap.playground/Resources/invoices.json b/0046-the-many-faces-of-flatmap-pt5/ManyFacesOfFlatMap.playground/Resources/invoices.json
new file mode 100644
index 00000000..8c0af97b
--- /dev/null
+++ b/0046-the-many-faces-of-flatmap-pt5/ManyFacesOfFlatMap.playground/Resources/invoices.json
@@ -0,0 +1,14 @@
+[
+  {
+    "amountPaid": 1000,
+    "amountDue": 0,
+    "closed": true,
+    "id": 1
+  },
+  {
+    "amountPaid": 500,
+    "amountDue": 500,
+    "closed": false,
+    "id": 2
+  }
+]
diff --git a/0046-the-many-faces-of-flatmap-pt5/ManyFacesOfFlatMap.playground/Resources/user.json b/0046-the-many-faces-of-flatmap-pt5/ManyFacesOfFlatMap.playground/Resources/user.json
new file mode 100644
index 00000000..ae6fc81d
--- /dev/null
+++ b/0046-the-many-faces-of-flatmap-pt5/ManyFacesOfFlatMap.playground/Resources/user.json
@@ -0,0 +1,5 @@
+{
+  "email": "blob@pointfree.co",
+  "id": 42,
+  "name": "Blob"
+}
diff --git a/0046-the-many-faces-of-flatmap-pt5/ManyFacesOfFlatMap.playground/Sources/Util.swift b/0046-the-many-faces-of-flatmap-pt5/ManyFacesOfFlatMap.playground/Sources/Util.swift
new file mode 100644
index 00000000..e8ec0129
--- /dev/null
+++ b/0046-the-many-faces-of-flatmap-pt5/ManyFacesOfFlatMap.playground/Sources/Util.swift
@@ -0,0 +1,17 @@
+precedencegroup EffectfulComposition {
+  associativity: left
+  higherThan: AssignmentPrecedence
+}
+
+infix operator >=>: EffectfulComposition
+
+precedencegroup ForwardComposition {
+  associativity: left
+  higherThan: EffectfulComposition
+}
+
+infix operator >>>: ForwardComposition
+
+public func >>> <A, B, C>(f: @escaping (A) -> B, g: @escaping (B) -> C) -> (A) -> C {
+  return { a in g(f(a)) }
+}
diff --git a/0046-the-many-faces-of-flatmap-pt5/ManyFacesOfFlatMap.playground/contents.xcplayground b/0046-the-many-faces-of-flatmap-pt5/ManyFacesOfFlatMap.playground/contents.xcplayground
new file mode 100644
index 00000000..a93d4844
--- /dev/null
+++ b/0046-the-many-faces-of-flatmap-pt5/ManyFacesOfFlatMap.playground/contents.xcplayground
@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<playground version='5.0' target-platform='macos' executeOnSourceChanges='false'>
+    <timeline fileName='timeline.xctimeline'/>
+</playground>
\ No newline at end of file
diff --git a/0046-the-many-faces-of-flatmap-pt5/ManyFacesOfFlatMap.xcworkspace/contents.xcworkspacedata b/0046-the-many-faces-of-flatmap-pt5/ManyFacesOfFlatMap.xcworkspace/contents.xcworkspacedata
new file mode 100644
index 00000000..cb4198ae
--- /dev/null
+++ b/0046-the-many-faces-of-flatmap-pt5/ManyFacesOfFlatMap.xcworkspace/contents.xcworkspacedata
@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Workspace
+   version = "1.0">
+   <FileRef
+      location = "group:ManyFacesOfFlatMap.playground">
+   </FileRef>
+   <FileRef
+      location = "group:ManyFacesOfFlatMap.xcodeproj">
+   </FileRef>
+</Workspace>
diff --git a/0046-the-many-faces-of-flatmap-pt5/ManyFacesOfFlatMap.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist b/0046-the-many-faces-of-flatmap-pt5/ManyFacesOfFlatMap.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist
new file mode 100644
index 00000000..18d98100
--- /dev/null
+++ b/0046-the-many-faces-of-flatmap-pt5/ManyFacesOfFlatMap.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist
@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>IDEDidComputeMac32BitWarning</key>
+	<true/>
+</dict>
+</plist>
diff --git a/0046-the-many-faces-of-flatmap-pt5/ManyFacesOfFlatMap.xcworkspace/xcshareddata/WorkspaceSettings.xcsettings b/0046-the-many-faces-of-flatmap-pt5/ManyFacesOfFlatMap.xcworkspace/xcshareddata/WorkspaceSettings.xcsettings
new file mode 100644
index 00000000..a72dc2b4
--- /dev/null
+++ b/0046-the-many-faces-of-flatmap-pt5/ManyFacesOfFlatMap.xcworkspace/xcshareddata/WorkspaceSettings.xcsettings
@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+    <key>IDEWorkspaceSharedSettings_AutocreateContextsIfNeeded</key>
+    <false/>
+</dict>
+</plist>
\ No newline at end of file
diff --git a/0046-the-many-faces-of-flatmap-pt5/Package.resolved b/0046-the-many-faces-of-flatmap-pt5/Package.resolved
new file mode 100644
index 00000000..933b69f4
--- /dev/null
+++ b/0046-the-many-faces-of-flatmap-pt5/Package.resolved
@@ -0,0 +1,16 @@
+{
+  "object": {
+    "pins": [
+      {
+        "package": "NonEmpty",
+        "repositoryURL": "https://github.com/pointfreeco/swift-nonempty.git",
+        "state": {
+          "branch": null,
+          "revision": "bcf639e8ec6c20b6b7b28ed9bfa0fe83450c3248",
+          "version": "0.1.2"
+        }
+      }
+    ]
+  },
+  "version": 1
+}
diff --git a/0046-the-many-faces-of-flatmap-pt5/Package.swift b/0046-the-many-faces-of-flatmap-pt5/Package.swift
new file mode 100644
index 00000000..156e9c16
--- /dev/null
+++ b/0046-the-many-faces-of-flatmap-pt5/Package.swift
@@ -0,0 +1,24 @@
+// swift-tools-version:4.2
+// The swift-tools-version declares the minimum version of Swift required to build this package.
+
+import PackageDescription
+
+let package = Package(
+    name: "ManyFacesOfFlatMap",
+    products: [
+        // Products define the executables and libraries produced by a package, and make them visible to other packages.
+        .library(
+            name: "ManyFacesOfFlatMap",
+            targets: ["ManyFacesOfFlatMap"]),
+    ],
+    dependencies: [
+        .package(url: "https://github.com/pointfreeco/swift-nonempty.git", from: "0.1.2")
+    ],
+    targets: [
+        // Targets are the basic building blocks of a package. A target can define a module or a test suite.
+        // Targets can depend on other targets in this package, and on products in packages which this package depends on.
+        .target(
+            name: "ManyFacesOfFlatMap",
+            dependencies: ["NonEmpty"])
+    ]
+)
diff --git a/0046-the-many-faces-of-flatmap-pt5/README.md b/0046-the-many-faces-of-flatmap-pt5/README.md
new file mode 100644
index 00000000..4e2fc55c
--- /dev/null
+++ b/0046-the-many-faces-of-flatmap-pt5/README.md
@@ -0,0 +1,14 @@
+## [Point-Free](https://www.pointfree.co)
+
+> #### This directory contains code from Point-Free Episode: [The Many Faces of Flat-Map: Part 5](https://www.pointfree.co/episodes/ep46-the-many-faces-of-flat-map-part-5)
+>
+> Continuing our 3-part answer to the all-important question "what's the point?", we finally show that standing on the foundation of our understanding of `map`, `zip` and `flatMap` we can now ask and concisely answer very complex questions about the nature of these operations.
+
+### Getting Started
+
+* Clone repo
+* `cd` into this directory
+* Run `swift package generate-xcodeproj`
+* Open `ManyFacesOfFlatMap.xcworkspace`
+* Build the package for _macOS_
+* Open the playground
diff --git a/0046-the-many-faces-of-flatmap-pt5/Sources/ManyFacesOfFlatMap/ManyFacesOfFlatMap.swift b/0046-the-many-faces-of-flatmap-pt5/Sources/ManyFacesOfFlatMap/ManyFacesOfFlatMap.swift
new file mode 100644
index 00000000..8fcf9749
--- /dev/null
+++ b/0046-the-many-faces-of-flatmap-pt5/Sources/ManyFacesOfFlatMap/ManyFacesOfFlatMap.swift
@@ -0,0 +1,2 @@
+
+let x = 1