Checkpoint

src/prolog/builtins/control.kt

@@ -0,0 +1,20 @@
+package prolog.builtins
+
+import prolog.components.terms.Atom
+
+/**
+ * Always fail.
+ */
+class Fail: Atom("fail")
+
+/**
+ * Same as fail, but the name has a more declarative connotation.
+ */
+typealias False = Fail
+
+/**
+ * Always succeed.
+ */
+class True: Atom("true")
+
+// TODO Repeat/0