diff --git a/.gitignore b/.gitignore
index ee508f76..4bcc085a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -8,3 +8,5 @@ pom.xml
 .lein-deps-sum
 .lein-failures
 .lein-plugins
+.idea/
+*.iml
diff --git a/.travis.yml b/.travis.yml
index 455f3c0e..aaa8fab7 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -2,7 +2,7 @@ language: clojure
 lein: lein2
 script: lein2 midje :config .midje-grading-config.clj
 jdk:
-  - openjdk7
+  - openjdk11
 notifications:
   email: false
   webhooks: http://polar-hollows-8825.herokuapp.com/notifications
diff --git a/project.clj b/project.clj
index a7ba528d..3bc3776f 100644
--- a/project.clj
+++ b/project.clj
@@ -1,5 +1,6 @@
 (defproject structured-data "1.0.0-SNAPSHOT"
-  :dependencies [[org.clojure/clojure "1.5.1"]
+  :dependencies [[org.clojure/clojure "1.10.0"]
                  [iloveponies.tests/structured-data "0.1.0-SNAPSHOT"]]
-  :profiles {:dev {:plugins [[lein-midje "3.1.1"]]}})
+ :profiles {:dev {:dependencies [[midje "1.9.5" :exclusions [org.clojure/clojure]]]
+                   :plugins [[lein-midje "3.2.1"]]}})
 
diff --git a/src/structured_data.clj b/src/structured_data.clj
index ebfe1ce4..6021501f 100644
--- a/src/structured_data.clj
+++ b/src/structured_data.clj
@@ -1,16 +1,20 @@
 (ns structured-data)
 
 (defn do-a-thing [x]
-  :-)
+  (let [thing (+ x x)]
+    (Math/pow thing thing)))
 
 (defn spiff [v]
-  :-)
+  (let [first (get v 0)
+        second (get v 2)]
+    (+ first second)))
 
 (defn cutify [v]
-  :-)
+  (conj v "<3"))
 
 (defn spiff-destructuring [v]
-  :-)
+  (let [[a ? b] v]
+    (+ a b)))
 
 (defn point [x y]
   [x y])
@@ -19,96 +23,125 @@
   [bottom-left top-right])
 
 (defn width [rectangle]
-  :-)
+  (let [[[x1 ?] [x2 ?]] rectangle]
+    (- x2 x1)))
 
 (defn height [rectangle]
-  :-)
+  (let [[[? y1] [? y2]] rectangle]
+    (- y2 y1)))
 
 (defn square? [rectangle]
-  :-)
+  (== (height rectangle) (width rectangle)))
 
 (defn area [rectangle]
-  :-)
+  (* (height rectangle) (width rectangle)))
 
 (defn contains-point? [rectangle point]
-  :-)
+  (let [[[x1 y1] [x2 y2]] rectangle
+        [a b] point
+        left-in (>= a x1)
+        right-in (<= a x2)
+        bottom-in (>= b y1)
+        top-in (<= b y2)]
+    (and left-in right-in bottom-in top-in)
+    ))
 
 (defn contains-rectangle? [outer inner]
-  :-)
+  (let [[bottom-left top-right] inner
+        bottom-left-in (contains-point? outer bottom-left)
+        top-right-in (contains-point? outer top-right)]
+    (and bottom-left-in top-right-in)
+    ))
 
 (defn title-length [book]
-  :-)
+  (count (:title book)))
 
 (defn author-count [book]
-  :-)
+  (count (:authors book)))
 
 (defn multiple-authors? [book]
-  :-)
+  (> (author-count book) 1))
 
 (defn add-author [book new-author]
-  :-)
+  (let [new-authors (conj (:authors book) new-author)]
+    (assoc book :authors new-authors)))
 
 (defn alive? [author]
-  :-)
+  (not (contains? author :death-year)))
 
 (defn element-lengths [collection]
-  :-)
+  (map count collection))
 
 (defn second-elements [collection]
-  :-)
+  (let [second
+        (fn [coll] (get coll 1))]
+    (map second collection)))
 
 (defn titles [books]
-  :-)
-
-(defn monotonic? [a-seq]
-  :-)
+  (map :title books))
 
 (defn stars [n]
-  :-)
+  (apply str (repeat n "*")))
+
+(defn monotonic? [a-seq]
+  (or (apply <= a-seq) (apply >= a-seq)))
 
 (defn toggle [a-set elem]
-  :-)
+  (if (contains? a-set elem)
+    (disj a-set elem)
+    (conj a-set elem)))
 
 (defn contains-duplicates? [a-seq]
-  :-)
+  (< (count (set a-seq))
+     (count a-seq)))
 
 (defn old-book->new-book [book]
-  :-)
+  (let [authors (set (:authors book))]
+    (assoc book :authors authors)))
 
 (defn has-author? [book author]
-  :-)
+  (contains? (:authors book) author))
 
 (defn authors [books]
-  :-)
+  (set (apply concat (map :authors books))))
 
 (defn all-author-names [books]
-  :-)
+  (set (map :name (authors books))))
 
 (defn author->string [author]
-  :-)
+  (let [life-info
+        (fn [author] (if (or (:birth-year author) (:death-year author))
+                       (str " (" (:birth-year author) " - " (:death-year author) ")")))]
+    (apply str (:name author) (life-info author))))
 
 (defn authors->string [authors]
-  :-)
+  (apply str (interpose ", " (map author->string authors))))
 
 (defn book->string [book]
-  :-)
+  (apply str (interpose ", written by " [(:title book), (authors->string (authors [book]))])))
 
 (defn books->string [books]
-  :-)
+  (cond
+    (empty? books) "No books."
+    (= (count books) 1) (str "1 book. " (book->string (get books 0)) ".")
+    :else (str (count books) " books. " (apply str (interpose ". " (map book->string books))) ".")))
 
 (defn books-by-author [author books]
-  :-)
+  (filter (fn [book] (has-author? book author)) books))
 
 (defn author-by-name [name authors]
-  :-)
+  (let [results (filter (fn [author] (= name (:name author))) authors)]
+    (if (empty? results)
+      nil
+      (first results)))
+  )
 
 (defn living-authors [authors]
-  :-)
+  (filter (fn [author] (alive? author)) authors))
 
 (defn has-a-living-author? [book]
-  :-)
+  (< 0 (count (living-authors (:authors book)))))
 
 (defn books-by-living-authors [books]
-  :-)
+  (filter (fn [current] (has-a-living-author? current)) books))
 
-; %________%