Finished Chapter 4 of Clojure for the Brave and True

I have just finished the tasks at the end of Chapter 4 "Core Functions in Depth".
See my solutions below (hosted on github)
Some important lessons learned:

1. When inserting into a sequence, make sure that the new sequence to insert is of the right type. Consider the following code:
   
   

   (into [{:name "Edward Cullen" :glitter-index 10} 

          {:name "Bella Swan" :glitter-index 0} 
          {:name "Charlie Swan" :glitter-index 0}]
      {:name "Mr Bean" :glitter-index 5})
   

   
   Result:
   
   

   [{:name "Edward Cullen", :glitter-index 10} 

      {:name "Bella Swan", :glitter-index 0} 
      {:name "Charlie Swan", :glitter-index 0}

      [:name "Mr Bean"] [:glitter-index 5]]
   

   
   Since in this case, the new sequence is a map, each key-value pair is treated as a new vector.
   The right way to insert a new map entry is the following:
   
   

   (into [{:name "Edward Cullen" :glitter-index 10} 

          {:name "Bella Swan" :glitter-index 0} 
          {:name "Charlie Swan" glitter-index 0}]
       [{:name "Mr Bean" :glitter-index 5}])
   

   
   Result:
   
   

   [{:name "Edward Cullen", :glitter-index 10}

    {:name "Bella Swan", :glitter-index 0} 
    {:name "Charlie Swan", :glitter-index 0}

    {:name "Mr Bean", :glitter-index 5}]
   

   
   
   
2. and cannot be applied. There are some other ways to achieve the same result. One possible solution is the following:
   
   

      (apply = true '(true false true))