anchor.diff:  (.getElementById js/document "app")
   ----
   
  -Let's look a bit closer at the flags we've used here. `-m`, short
  -for `--main`, invokes a _Clojure_ function, in this case `cljs.main`. The
  -`cljs.main` function supports a variety of command line arguments to specify
  -common tasks. We're using `-c` for `--compile` to specify that we want to
  -compile the `hello-world.core` namespace. This is followed by `-r` for `--repl`
  -to say that we want a REPL to launch immediately when compilation completes.
  +Let's look a bit closer at the flags we've used here. `--main` invokes a
  +_Clojure_ function, in this case `cljs.main`. The `cljs.main` function supports
  +a variety of command line arguments to specify common tasks. We're using
  +`--compile` to specify that we want to compile the `hello-world.core`
  +namespace. This is followed by `--repl` to say that we want a REPL to
  +launch immediately when compilation completes.
   
   Change your `src/hello_world/core.cljs` source file to look like the following:
   
  
positive.code: elimination.
  
  You can test that this file still works by running the built in simple web
  server via the `-s` or `--serve` flag:
  
  [source,bash]
  ----
  clj -m cljs.main -s
  ----
  
  On Windows:
  
  [source,bash]
  ----
  java -cp "cljs.jar;src" -m cljs.main -s
  ----
  
  `-s` is for `--serve`. This command does not start a REPL, so a browser window
  
negative.code: 
  [source,bash]
  ----
  clj -m cljs.main --target node --output-to main.js -c hello-world.core
  ----
  
  On Windows:
  
  [source,bash]
  ----
  java -cp "cljs.jar;src" -m cljs.main --target node --output-to main.js -c hello-world.core
  ----
  
  You can run your file with:
  