There's a lot of precise, technical language, including a specification - that seems very contentful and specific to me.

The code examples seem very straightforward and compelling to me.

    > # Setup: Simple function on strings     
    > f = λa λb concat ["Hello ",a," ",b,"!"] 
    > f "Jane" "Doe"                          
    Hello Jane Doe!                           

This requires some familiarity with languages like Lisp or Forth to follow, but otherwise it's very straightforward.

    > # What else can we do with a function?  
    > g = f "Admiral"                         
    > # Try to invert it:                     
    > invert g "Hello Admiral 
    Alice!"         
    Alice

That's a really concise and impressive demo to me! I've never seen a language that can invert functions!