diff --git a/.env b/.env
new file mode 100644
index 0000000..a8a6553
--- /dev/null
+++ b/.env
@@ -0,0 +1 @@
+PORT=5555
diff --git a/OneVariableCalculus/Apostol.lean b/OneVariableCalculus/Apostol.lean
index 55a224e..f1c820b 100644
--- a/OneVariableCalculus/Apostol.lean
+++ b/OneVariableCalculus/Apostol.lean
@@ -1,3 +1,2 @@
 import OneVariableCalculus.Apostol.Chapter_I_3
-import OneVariableCalculus.Apostol.Exercises_1_7
-import OneVariableCalculus.Apostol.Exercises_I_3_12
\ No newline at end of file
+import OneVariableCalculus.Apostol.Exercises_I_3_12
diff --git a/OneVariableCalculus/Real/Set/Partition.lean b/OneVariableCalculus/Real/Set/Partition.lean
index faaccf4..462f6b1 100644
--- a/OneVariableCalculus/Real/Set/Partition.lean
+++ b/OneVariableCalculus/Real/Set/Partition.lean
@@ -81,7 +81,6 @@ theorem subdivision_point_leq_right {p : Partition} (h : x ∈ p.xs)
   have ⟨_, ⟨_, hs⟩⟩ := self_neq_nil_imp_exists_mem.mp hx
   by_cases hz : i = ⟨p.xs.length - 1, by rw [hs]; simp⟩
   · rw [hz]
-    simp
   · refine le_of_lt (Sorted.rel_get_of_lt p.sorted ?_)
     rw [← ne_eq, Fin.ne_iff_vne] at hz
     rw [Fin.lt_iff_val_lt_val]
diff --git a/README.md b/README.md
index 25f89a9..90ac946 100644
--- a/README.md
+++ b/README.md
@@ -13,3 +13,17 @@ LaTeX when not.
 - [ ] Gustedt, Jens. Modern C. Shelter Island, NY: Manning Publications Co, 2020.
 - [ ] Ross, Sheldon. A First Course in Probability Theory. 8th ed. Pearson Prentice Hall, n.d.
 - [ ] Smullyan, Raymond M. To Mock a Mockingbird: And Other Logic Puzzles Including an Amazing Adventure in Combinatory Logic. Oxford: Oxford university press, 2000.
+
+## Documentation
+
+To generate Lean documentation, we use [doc-gen4](https://github.com/leanprover/doc-gen4).
+Run the following to build and serve this:
+
+```bash
+> lake build Bookshelf:docs
+> lake run doc-server
+```
+
+This assumes you have `python3` available in your `$PATH`. To change how the
+server behaves, refer to the `.env` file located in the root directory of this
+project.
diff --git a/lake-manifest.json b/lake-manifest.json
index 7a65f57..043e52f 100644
--- a/lake-manifest.json
+++ b/lake-manifest.json
@@ -2,23 +2,59 @@
  "packagesDir": "lake-packages",
  "packages":
  [{"git":
+   {"url": "https://github.com/xubaiw/CMark.lean",
+    "subDir?": null,
+    "rev": "2cc7cdeef67184f84db6731450e4c2b258c28fe8",
+    "name": "CMark",
+    "inputRev?": "main"}},
+  {"git":
+   {"url": "https://github.com/leanprover/lake",
+    "subDir?": null,
+    "rev": "257fc59a6464f5732a4f49e7dda0fc37475819fb",
+    "name": "lake",
+    "inputRev?": "master"}},
+  {"git":
+   {"url": "https://github.com/leanprover/doc-gen4",
+    "subDir?": null,
+    "rev": "cf86cb481501e9f03dce5b0cb362b19cdba1824f",
+    "name": "doc-gen4",
+    "inputRev?": "cf86cb481501e9f03dce5b0cb362b19cdba1824f"}},
+  {"git":
+   {"url": "https://github.com/mhuisi/lean4-cli",
+    "subDir?": null,
+    "rev": "5a858c32963b6b19be0d477a30a1f4b6c120be7e",
+    "name": "Cli",
+    "inputRev?": "nightly"}},
+  {"git":
    {"url": "https://github.com/leanprover-community/mathlib4.git",
     "subDir?": null,
-    "rev": "0107c50abf149a48b5b9ad08a0b2a2093bcb567a",
+    "rev": "d65ed3b2920dbfb0b2bf1aca2189ec177eb68980",
     "name": "mathlib",
-    "inputRev?": "0107c50abf149a48b5b9ad08a0b2a2093bcb567a"}},
+    "inputRev?": "d65ed3b2920dbfb0b2bf1aca2189ec177eb68980"}},
   {"git":
    {"url": "https://github.com/gebner/quote4",
     "subDir?": null,
-    "rev": "7ae096b232087096ff0243a2b70d32720d2621ae",
+    "rev": "c71f94e34c1cda52eef5c93dc9da409ab2727420",
     "name": "Qq",
     "inputRev?": "master"}},
   {"git":
    {"url": "https://github.com/JLimperg/aesop",
     "subDir?": null,
-    "rev": "071464ac36e339afb7a87640aa1f8121f707a59a",
+    "rev": "cdc00b640d0179910ebaa9c931e3b733a04b881c",
     "name": "aesop",
     "inputRev?": "master"}},
+  {"git":
+   {"url": "https://github.com/hargonix/LeanInk",
+    "subDir?": null,
+    "rev": "2447df5cc6e48eb965c3c3fba87e46d353b5e9f1",
+    "name": "leanInk",
+    "inputRev?": "doc-gen"}},
+  {"git":
+   {"url": "https://github.com/fgdorais/lean4-unicode-basic",
+    "subDir?": null,
+    "rev": "be1f061688faa1dbb224773c54901661253fb4b8",
+    "name": "UnicodeBasic",
+    "inputRev?": "main"}},
   {"git":
    {"url": "https://github.com/leanprover/std4.git",
     "subDir?": null,
@@ -28,6 +64,6 @@
   {"git":
    {"url": "https://github.com/leanprover/std4",
     "subDir?": null,
-    "rev": "5507f9d8409f93b984ce04eccf4914d534e6fca2",
+    "rev": "6006307d2ceb8743fea7e00ba0036af8654d0347",
     "name": "std",
     "inputRev?": "main"}}]}
diff --git a/lakefile.lean b/lakefile.lean
index e8b0cb8..727f406 100644
--- a/lakefile.lean
+++ b/lakefile.lean
@@ -1,14 +1,18 @@
 import Lake
+
 open Lake DSL
 
 package «bookshelf»
 
 require mathlib from git
   "https://github.com/leanprover-community/mathlib4.git" @
-    "0107c50abf149a48b5b9ad08a0b2a2093bcb567a"
+    "d65ed3b2920dbfb0b2bf1aca2189ec177eb68980"
 require std4 from git
   "https://github.com/leanprover/std4.git" @
     "6006307d2ceb8743fea7e00ba0036af8654d0347"
+require «doc-gen4» from git
+  "https://github.com/leanprover/doc-gen4" @
+    "cf86cb481501e9f03dce5b0cb362b19cdba1824f"
 
 @[default_target]
 lean_lib «Bookshelf» {
@@ -21,3 +25,40 @@ lean_lib «Bookshelf» {
     `TheoremProvingInLean
   ]
 }
+
+/--
+The contents of our `.env` file.
+-/
+structure Config where
+  port : Nat := 5555
+
+/--
+Read in the `.env` file into an in-memory structure.
+-/
+private def readConfig : StateT Config ScriptM Unit := do
+  let env <- IO.FS.readFile ".env"
+  for line in env.trim.split (fun c => c == '\n') do
+    match line.split (fun c => c == '=') with
+    | ["PORT", port] => modify (fun c => { c with port := String.toNat! port })
+    | _ => error "Malformed `.env` file."
+  return ()
+
+/--
+Start an HTTP server for locally serving documentation. It is expected the
+documentation has already been generated prior via
+
+```bash
+> lake build Bookshelf:docs
+```
+
+USAGE:
+  lake run doc-server
+-/
+script «doc-server» (_args) do
+  let ((), config) <- StateT.run readConfig {}
+  IO.println s!"Running on `http://localhost:{config.port}`"
+  _ <- IO.Process.run {
+    cmd := "python3",
+    args := #["-m", "http.server", toString config.port, "-d", "build/doc"],
+  }
+  return 0
diff --git a/lean-toolchain b/lean-toolchain
index d30699b..03ae79e 100644
--- a/lean-toolchain
+++ b/lean-toolchain
@@ -1 +1 @@
-leanprover/lean4:nightly-2023-04-02
+leanprover/lean4:nightly-2023-04-20