diff --git a/AlgebraicDataflowArchitectureModel/models/Citrus.model b/AlgebraicDataflowArchitectureModel/models/Citrus.model
new file mode 100644
index 0000000..a4cd25b
--- /dev/null
+++ b/AlgebraicDataflowArchitectureModel/models/Citrus.model
@@ -0,0 +1,69 @@
+channel Signup {
+    out accounts(accDB:Map, signup(aid:Str)) = insert(accDB, aid, {"favorites": nil, "books": nil})
+}
+
+channel CreateBook(aid:Str) {
+    out accounts.{aid}.books(bookList:List, createBook(title:Str)) = append(bookList, {"title": title, "todos": nil, "favorited": nil})
+}
+
+channel DeleteAccount {
+	out accounts(accDB:Map, deleteAccount(aid:Str)) = if(contains(accDB, aid), delete(accDB, aid), accDB)
+}
+
+channel ChangeAccountName {
+    out accounts(accDB:Map, changeAccountId(aid:Str, newAid:Str)) = if(aid == newAid, accDB, delete(insert(accDB, newAid, lookup(accDB, aid)), aid))
+}
+
+channel ChangeBookName(aid:Str, bid:Int) {
+    out accounts.{aid}.books.{bid}.title(title:Str, changeBookName(newTitle)) = newTitle
+}
+
+channel DeleteBook(aid:Str) {
+	out accounts.{aid}.books(bookList:List, deleteBook(bid:int)) = if(bid < length(bookList), remove(bookList, bid), bookList)
+}
+
+channel CreateToDo(aid:Str, bid:Int) {
+    out accounts.{aid}.books.{bid}.todos(toDoDB:Map, createtodo(year:Str, month:Str, day:Str, title:Str)) = insert(toDoDB, 
+    																												year, 
+		                                                                                                        	insert(lookup(toDoDB, year), 
+		                                                                                                        			month, 
+	    	                                                                                                    			insert(lookup(lookup(toDoDB, year), month), 
+	    	                                                                                                    					day, 
+																																	append(lookup(lookup(lookup(toDoDB, year), month), day), 
+																																			{"title": title, "check": false}))))
+}
+
+channel ChangeToDoName(aid:Str, bid:Int, year:Str, month:Str, day:Str, tid:Int) {
+    out accounts.{aid}.books.{bid}.todos.{year}.{month}.{day}.{tid}.title(title:Str, changeToDoName(newTitle)) = newTitle
+}
+
+channel ChangeCheck(aid:Str, bid:Int, year:Str, month:Str, day:Str, tid:Int) {
+	out accounts.{aid}.books.{bid}.todos.{year}.{month}.{day}.{tid}.check(check:Bool, changeCheck(newCheck)) = newCheck
+}
+
+channel DeleteToDo(aid:Str, bid:Int) {
+    out accounts.{aid}.books.{bid}.todos(toDoDB:Map, deleteToDo(year:Str, month:Str, day:Str, tid:int)) = insert(toDoDB, 
+    																											year,
+                                                                                                        		insert(lookup(toDoDB, year), 
+                                                                                                        				month, 
+                                                                                                        				insert(lookup(lookup(toDoDB, year), month), 
+                                                                                                        						day, 
+                                                                                                        						remove(lookup(lookup(lookup(toDoDB, year), month), day),
+                                                                                                        								tid))))
+}
+
+channel AddFavorited(aid:Str, bid:Int) {
+    out accounts.{aid}.books.{bid}.favorited(faList:List, addFavorited(o_aid:Str)) = if(aid==o_aid, 
+    																					faList, 
+    																					if(contains(faList, o_aid), 
+    																						remove(faList, indexOf(faList, o_aid)), 
+    																						append(faList, o_aid)))
+    out accounts.{o_aid}.favorites(aDB:Map, addFavorited(o_aid:Str)) 
+                                        = if(aid==o_aid,
+                                              aDB,
+                                              if(contains(aDB, aid),
+                                                  if(contains(lookup(aDB, aid), bid), 
+                                                      insert(aDB, aid, remove(lookup(aDB, aid), indexOf(lookup(aDB, aid), bid))),
+                                                      insert(aDB, aid, append(lookup(aDB, aid), bid))), 
+                                                  insert(aDB, aid, append(nil, bid))))
+}