diff --git a/.prettierignore b/.prettierignore
index c47d4a1..ecd3d1e 100644
--- a/.prettierignore
+++ b/.prettierignore
@@ -4,3 +4,4 @@
 /docs/
 /build/
 CHANGELOG.md
+flake.lock
diff --git a/flake.lock b/flake.lock
index 9bf9edf..46da292 100644
--- a/flake.lock
+++ b/flake.lock
@@ -1,63 +1,79 @@
 {
-    "nodes": {
-        "flake-parts": {
-            "inputs": {
-                "nixpkgs-lib": "nixpkgs-lib"
-            },
-            "locked": {
-                "lastModified": 1680392223,
-                "narHash": "sha256-n3g7QFr85lDODKt250rkZj2IFS3i4/8HBU2yKHO3tqw=",
-                "owner": "hercules-ci",
-                "repo": "flake-parts",
-                "rev": "dcc36e45d054d7bb554c9cdab69093debd91a0b5",
-                "type": "github"
-            },
-            "original": {
-                "id": "flake-parts",
-                "type": "indirect"
-            }
-        },
-        "nixpkgs": {
-            "locked": {
-                "lastModified": 1680942619,
-                "narHash": "sha256-kpCW1IegAZfEjCVJW7IPN/hEtRL/9dxaFFYiHS5qVAk=",
-                "owner": "NixOS",
-                "repo": "nixpkgs",
-                "rev": "6f95dd4fd050daf017cae2dfeb1cea1ec0e4c1a1",
-                "type": "github"
-            },
-            "original": {
-                "owner": "NixOS",
-                "ref": "nixpkgs-unstable",
-                "repo": "nixpkgs",
-                "type": "github"
-            }
-        },
-        "nixpkgs-lib": {
-            "locked": {
-                "dir": "lib",
-                "lastModified": 1680213900,
-                "narHash": "sha256-cIDr5WZIj3EkKyCgj/6j3HBH4Jj1W296z7HTcWj1aMA=",
-                "owner": "NixOS",
-                "repo": "nixpkgs",
-                "rev": "e3652e0735fbec227f342712f180f4f21f0594f2",
-                "type": "github"
-            },
-            "original": {
-                "dir": "lib",
-                "owner": "NixOS",
-                "ref": "nixos-unstable",
-                "repo": "nixpkgs",
-                "type": "github"
-            }
-        },
-        "root": {
-            "inputs": {
-                "flake-parts": "flake-parts",
-                "nixpkgs": "nixpkgs"
-            }
-        }
+  "nodes": {
+    "flake-parts": {
+      "inputs": {
+        "nixpkgs-lib": "nixpkgs-lib"
+      },
+      "locked": {
+        "lastModified": 1696343447,
+        "narHash": "sha256-B2xAZKLkkeRFG5XcHHSXXcP7To9Xzr59KXeZiRf4vdQ=",
+        "owner": "hercules-ci",
+        "repo": "flake-parts",
+        "rev": "c9afaba3dfa4085dbd2ccb38dfade5141e33d9d4",
+        "type": "github"
+      },
+      "original": {
+        "id": "flake-parts",
+        "type": "indirect"
+      }
     },
-    "root": "root",
-    "version": 7
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1697915759,
+        "narHash": "sha256-WyMj5jGcecD+KC8gEs+wFth1J1wjisZf8kVZH13f1Zo=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "51d906d2341c9e866e48c2efcaac0f2d70bfd43e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixpkgs-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "nixpkgs-lib": {
+      "locked": {
+        "dir": "lib",
+        "lastModified": 1696019113,
+        "narHash": "sha256-X3+DKYWJm93DRSdC5M6K5hLqzSya9BjibtBsuARoPco=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "f5892ddac112a1e9b3612c39af1b72987ee5783a",
+        "type": "github"
+      },
+      "original": {
+        "dir": "lib",
+        "owner": "NixOS",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "flake-parts": "flake-parts",
+        "nixpkgs": "nixpkgs",
+        "systems": "systems"
+      }
+    },
+    "systems": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
 }
diff --git a/flake.nix b/flake.nix
index fb016d5..bbf2348 100644
--- a/flake.nix
+++ b/flake.nix
@@ -2,141 +2,128 @@
   description = "Category Theory for Programmers";
 
   inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
+  inputs.systems.url = "github:nix-systems/default";
 
-  outputs = inputs @ {
-    self,
-    flake-parts,
-    nixpkgs,
-  }:
-    flake-parts.lib.mkFlake {inherit inputs;} {
-      systems = [
-        "x86_64-linux"
-        "x86_64-darwin"
-        "aarch64-linux"
-        "aarch64-darwin"
-      ];
+  outputs = inputs@{ self, flake-parts, nixpkgs, ... }:
+    flake-parts.lib.mkFlake { inherit inputs; } {
+      systems = import inputs.systems;
 
-      perSystem = {
-        config,
-        pkgs,
-        system,
-        ...
-      }: let
-        inherit (nixpkgs) lib;
+      perSystem = { config, pkgs, system, lib, ... }:
+        let
+          pkgs = nixpkgs.legacyPackages.${system};
 
-        pkgs = nixpkgs.legacyPackages.${system};
+          ########################################################################
+          # LaTeX Font
+          inconsolata-lgc-latex = pkgs.stdenvNoCC.mkDerivation {
+            name = "inconsolata-lgc-latex";
+            pname = "inconsolata-lgc-latex";
 
-        ########################################################################
-        # LaTeX Font
-        inconsolata-lgc-latex = pkgs.stdenvNoCC.mkDerivation {
-          name = "inconsolata-lgc-latex";
-          pname = "inconsolata-lgc-latex";
+            src = pkgs.inconsolata-lgc;
 
-          src = pkgs.inconsolata-lgc;
+            dontConfigure = true;
+            sourceRoot = ".";
 
-          dontConfigure = true;
-          sourceRoot = ".";
+            installPhase = ''
+              runHook preInstall
 
-          installPhase = ''
-            runHook preInstall
+              find $src -name '*.ttf' -exec install -m644 -Dt $out/fonts/truetype/public/inconsolata-lgc/ {} \;
+              find $src -name '*.otf' -exec install -m644 -Dt $out/fonts/opentype/public/inconsolata-lgc/ {} \;
 
-            find $src -name '*.ttf' -exec install -m644 -Dt $out/fonts/truetype/public/inconsolata-lgc/ {} \;
-            find $src -name '*.otf' -exec install -m644 -Dt $out/fonts/opentype/public/inconsolata-lgc/ {} \;
+              runHook postInstall
+            '';
 
-            runHook postInstall
-          '';
-
-          tlType = "run";
-        };
-
-        ########################################################################
-        # LaTeX Environment
-        texliveEnv = pkgs.texlive.combine {
-          inherit
-            (pkgs.texlive)
-            adjustbox
-            alegreya
-            babel
-            bookcover
-            catchfile
-            chngcntr
-            collectbox
-            currfile
-            emptypage
-            enumitem
-            environ
-            fgruler
-            fontaxes
-            framed
-            fvextra
-            idxlayout
-            ifmtarg
-            ifnextok
-            ifplatform
-            imakeidx
-            import
-            inconsolata
-            l3packages
-            lettrine
-            libertine
-            libertinus-fonts
-            listings
-            mdframed
-            microtype
-            minifp
-            minted
-            mweights
-            needspace
-            newtx
-            noindentafter
-            nowidow
-            scheme-medium
-            subfigure
-            subfiles
-            textpos
-            tcolorbox
-            tikz-cd
-            titlecaps
-            titlesec
-            todonotes
-            trimspaces
-            upquote
-            wrapfig
-            xifthen
-            xpatch
-            xstring
-            zref
-            ;
-
-          inconsolata-lgc-latex = {
-            pkgs = [inconsolata-lgc-latex];
+            tlType = "run";
           };
-        };
 
-        commonAttrs = {
-          nativeBuildInputs = [
-            texliveEnv
-            (
-              pkgs.python3.withPackages (p: [p.pygments p.pygments-style-github])
-            )
-            pkgs.which
-          ];
-        };
+          ########################################################################
+          # LaTeX Environment
+          texliveEnv = pkgs.texlive.combine {
+            inherit
+              (pkgs.texlive)
+              adjustbox
+              alegreya
+              babel
+              bookcover
+              catchfile
+              chngcntr
+              collectbox
+              currfile
+              emptypage
+              enumitem
+              environ
+              fgruler
+              fontaxes
+              framed
+              fvextra
+              idxlayout
+              ifmtarg
+              ifnextok
+              ifplatform
+              imakeidx
+              import
+              inconsolata
+              l3packages
+              lettrine
+              libertine
+              libertinus-fonts
+              listings
+              mdframed
+              microtype
+              minifp
+              minted
+              mweights
+              needspace
+              newtx
+              noindentafter
+              nowidow
+              scheme-medium
+              subfigure
+              subfiles
+              textpos
+              tcolorbox
+              tikz-cd
+              titlecaps
+              titlesec
+              todonotes
+              trimspaces
+              upquote
+              wrapfig
+              xifthen
+              xpatch
+              xstring
+              zref
+              ;
 
-        mkLatex = variant: edition: let
-          maybeVariant = lib.optionalString (variant != null) "-${variant}";
-          maybeEdition = lib.optionalString (edition != null) "-${edition}";
-          variantStr =
-            if variant == null
-            then "reader"
-            else variant;
-          basename = "ctfp-${variantStr}${maybeEdition}";
-          version = self.shortRev or self.lastModifiedDate;
-          suffix = maybeVariant + maybeEdition;
-          fullname = "ctfp${suffix}";
-        in
-          pkgs.stdenvNoCC.mkDerivation (commonAttrs
-            // {
+            inconsolata-lgc-latex = {
+              pkgs = [ inconsolata-lgc-latex ];
+            };
+          };
+
+          commonAttrs = {
+            nativeBuildInputs = [
+              texliveEnv
+              (
+                pkgs.python3.withPackages (p: [ p.pygments p.pygments-style-github ])
+              )
+              pkgs.which
+            ];
+          };
+
+          mkLatex = variant: edition:
+            let
+              maybeVariant = lib.optionalString (variant != null) "-${variant}";
+              maybeEdition = lib.optionalString (edition != null) "-${edition}";
+              variantStr =
+                if variant == null
+                then "reader"
+                else variant;
+              basename = "ctfp-${variantStr}${maybeEdition}";
+              version = self.shortRev or self.lastModifiedDate;
+              suffix = maybeVariant + maybeEdition;
+              fullname = "ctfp${suffix}";
+            in
+            pkgs.stdenvNoCC.mkDerivation (commonAttrs
+              // {
               inherit basename version;
               name = basename;
 
@@ -161,34 +148,43 @@
                 runHook postBuild
               '';
 
-              installPhase = "install -m 0644 -vD ctfp.pdf \"$out/${fullname}.pdf\"";
+              installPhase = "
+                runHook preInstall
+
+                install -m 0644 -vD ctfp.pdf \"$out/${fullname}.pdf\"
+
+                runHook postInstall
+              ";
 
               passthru.packageName = fullname;
             });
 
-        editions = [null "scala" "ocaml" "reason"];
-        variants = [null "print"];
-      in rec {
-        formatter = pkgs.alejandra;
+          editions = [ null "scala" "ocaml" "reason" ];
+          variants = [ null "print" ];
+        in
+        {
+          formatter = pkgs.nixpkgs-fmt;
 
-        packages = lib.listToAttrs (lib.concatMap (variant:
-          map (edition: rec {
-            name = value.packageName;
-            value = mkLatex variant edition;
-          })
-          editions)
-        variants);
+          packages = lib.listToAttrs (lib.concatMap
+            (variant:
+              map
+                (edition: rec {
+                  value = mkLatex variant edition;
+                  name = value.packageName;
+                })
+                editions)
+            variants);
 
-        # nix develop .
-        devShells.default = pkgs.mkShellNoCC (commonAttrs
-          // {
+          # nix develop .
+          devShells.default = pkgs.mkShellNoCC (commonAttrs
+            // {
             nativeBuildInputs =
               commonAttrs.nativeBuildInputs
-              ++ [
+                ++ [
                 pkgs.git
                 pkgs.gnumake
               ];
           });
-      };
+        };
     };
 }