[nix] keep default.nix simple

default.nix

 { pkgs ? import <nixpkgs> {} }:
 with pkgs;
-let texlive = pkgs.texlive.combine {
-    inherit (pkgs.texlive)
-    everypage
-    scheme-full
-    xkeyval
-    times
-    courier
-    wrapfig
-    xcolor
-    booktabs
-    caption
-    siunitx
-    fixme
-    todo
-    tabulary
-    algorithms
-    algorithmicx
-    acmart
-    totpages
-    environ
-    trimspaces
-    ncctools
-    comment
-    dirtree ;
-  };
-  inputs = [ texlive pkgs.dia rubber ninja ];
+let
+  texlive = pkgs.texlive.combined.scheme-minimal;
 in
+  stdenv.mkDerivation rec {
+    name = "slides";
+    src = ./.;
+    buildInputs = [ texlive pkgs.dia rubber ninja ];
+    buildPhase = "make";
 
-stdenv.mkDerivation rec {
-
-  name="paper";
-  src = ./.;
-  buildPhase = "make";
-
-  buildInputs = inputs;
-  installPhase = ''
-    mkdir $out
-    cp slides.pdf $out
+    installPhase = ''
+      mkdir $out
+      cp slides.pdf $out
     '';
-}
+  }