diff --git a/1_k/1_lambda/lesson_1/tests/closed-variable-capture.lambda.out b/1_k/1_lambda/lesson_1/tests/closed-variable-capture.lambda.out
index 989ddb0d..a621bf3d 100644
--- a/1_k/1_lambda/lesson_1/tests/closed-variable-capture.lambda.out
+++ b/1_k/1_lambda/lesson_1/tests/closed-variable-capture.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  ( lambda z . ( z z ) ) lambda x . lambda y . ( x y ) ~> .
+  ( lambda z . ( z z ) ) lambda x . lambda y . ( x y ) ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_1/tests/free-variable-capture.lambda.out b/1_k/1_lambda/lesson_1/tests/free-variable-capture.lambda.out
index 453eeb2a..e50d2392 100644
--- a/1_k/1_lambda/lesson_1/tests/free-variable-capture.lambda.out
+++ b/1_k/1_lambda/lesson_1/tests/free-variable-capture.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  a ( ( lambda x . lambda y . x ) y z ) ~> .
+  a ( ( lambda x . lambda y . x ) y z ) ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_1/tests/identity.lambda.out b/1_k/1_lambda/lesson_1/tests/identity.lambda.out
index 46c620ac..9476ee41 100644
--- a/1_k/1_lambda/lesson_1/tests/identity.lambda.out
+++ b/1_k/1_lambda/lesson_1/tests/identity.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  lambda x . x ~> .
+  lambda x . x ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_1/tests/omega.lambda.out b/1_k/1_lambda/lesson_1/tests/omega.lambda.out
index 9c9ebb87..35fae571 100644
--- a/1_k/1_lambda/lesson_1/tests/omega.lambda.out
+++ b/1_k/1_lambda/lesson_1/tests/omega.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  ( lambda x . ( x x ) ) lambda x . ( x x ) ~> .
+  ( lambda x . ( x x ) ) lambda x . ( x x ) ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_2.5/tests/closed-variable-capture.lambda.out b/1_k/1_lambda/lesson_2.5/tests/closed-variable-capture.lambda.out
index 45c65694..36ec35a9 100644
--- a/1_k/1_lambda/lesson_2.5/tests/closed-variable-capture.lambda.out
+++ b/1_k/1_lambda/lesson_2.5/tests/closed-variable-capture.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  lambda y . lambda y0 . ( y y0 ) ~> .
+  lambda y . lambda y0 . ( y y0 ) ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_2.5/tests/free-variable-capture.lambda.out b/1_k/1_lambda/lesson_2.5/tests/free-variable-capture.lambda.out
index ea4c74bd..556ded24 100644
--- a/1_k/1_lambda/lesson_2.5/tests/free-variable-capture.lambda.out
+++ b/1_k/1_lambda/lesson_2.5/tests/free-variable-capture.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  a y ~> .
+  a y ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_2.5/tests/identity.lambda.out b/1_k/1_lambda/lesson_2.5/tests/identity.lambda.out
index 46c620ac..9476ee41 100644
--- a/1_k/1_lambda/lesson_2.5/tests/identity.lambda.out
+++ b/1_k/1_lambda/lesson_2.5/tests/identity.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  lambda x . x ~> .
+  lambda x . x ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_2/tests/closed-variable-capture.lambda.out b/1_k/1_lambda/lesson_2/tests/closed-variable-capture.lambda.out
index c79d05f4..4134bc85 100644
--- a/1_k/1_lambda/lesson_2/tests/closed-variable-capture.lambda.out
+++ b/1_k/1_lambda/lesson_2/tests/closed-variable-capture.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  lambda y . ( ( lambda x . lambda y . ( x y ) ) y ) ~> .
+  lambda y . ( ( lambda x . lambda y . ( x y ) ) y ) ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_2/tests/free-variable-capture.lambda.out b/1_k/1_lambda/lesson_2/tests/free-variable-capture.lambda.out
index 453eeb2a..e50d2392 100644
--- a/1_k/1_lambda/lesson_2/tests/free-variable-capture.lambda.out
+++ b/1_k/1_lambda/lesson_2/tests/free-variable-capture.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  a ( ( lambda x . lambda y . x ) y z ) ~> .
+  a ( ( lambda x . lambda y . x ) y z ) ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_2/tests/identity.lambda.out b/1_k/1_lambda/lesson_2/tests/identity.lambda.out
index 46c620ac..9476ee41 100644
--- a/1_k/1_lambda/lesson_2/tests/identity.lambda.out
+++ b/1_k/1_lambda/lesson_2/tests/identity.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  lambda x . x ~> .
+  lambda x . x ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_3/tests/closed-variable-capture.lambda.out b/1_k/1_lambda/lesson_3/tests/closed-variable-capture.lambda.out
index c79d05f4..4134bc85 100644
--- a/1_k/1_lambda/lesson_3/tests/closed-variable-capture.lambda.out
+++ b/1_k/1_lambda/lesson_3/tests/closed-variable-capture.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  lambda y . ( ( lambda x . lambda y . ( x y ) ) y ) ~> .
+  lambda y . ( ( lambda x . lambda y . ( x y ) ) y ) ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_3/tests/free-variable-capture.lambda.out b/1_k/1_lambda/lesson_3/tests/free-variable-capture.lambda.out
index ea4c74bd..556ded24 100644
--- a/1_k/1_lambda/lesson_3/tests/free-variable-capture.lambda.out
+++ b/1_k/1_lambda/lesson_3/tests/free-variable-capture.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  a y ~> .
+  a y ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_3/tests/identity.lambda.out b/1_k/1_lambda/lesson_3/tests/identity.lambda.out
index 46c620ac..9476ee41 100644
--- a/1_k/1_lambda/lesson_3/tests/identity.lambda.out
+++ b/1_k/1_lambda/lesson_3/tests/identity.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  lambda x . x ~> .
+  lambda x . x ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_4/tests/closed-variable-capture.lambda.out b/1_k/1_lambda/lesson_4/tests/closed-variable-capture.lambda.out
index c79d05f4..4134bc85 100644
--- a/1_k/1_lambda/lesson_4/tests/closed-variable-capture.lambda.out
+++ b/1_k/1_lambda/lesson_4/tests/closed-variable-capture.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  lambda y . ( ( lambda x . lambda y . ( x y ) ) y ) ~> .
+  lambda y . ( ( lambda x . lambda y . ( x y ) ) y ) ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_4/tests/free-variable-capture.lambda.out b/1_k/1_lambda/lesson_4/tests/free-variable-capture.lambda.out
index ea4c74bd..556ded24 100644
--- a/1_k/1_lambda/lesson_4/tests/free-variable-capture.lambda.out
+++ b/1_k/1_lambda/lesson_4/tests/free-variable-capture.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  a y ~> .
+  a y ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_4/tests/identity.lambda.out b/1_k/1_lambda/lesson_4/tests/identity.lambda.out
index 46c620ac..9476ee41 100644
--- a/1_k/1_lambda/lesson_4/tests/identity.lambda.out
+++ b/1_k/1_lambda/lesson_4/tests/identity.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  lambda x . x ~> .
+  lambda x . x ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_5/tests/arithmetic.lambda.out b/1_k/1_lambda/lesson_5/tests/arithmetic.lambda.out
index 12360172..97f10093 100644
--- a/1_k/1_lambda/lesson_5/tests/arithmetic.lambda.out
+++ b/1_k/1_lambda/lesson_5/tests/arithmetic.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  true ~> .
+  true ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_5/tests/closed-variable-capture.lambda.out b/1_k/1_lambda/lesson_5/tests/closed-variable-capture.lambda.out
index c79d05f4..4134bc85 100644
--- a/1_k/1_lambda/lesson_5/tests/closed-variable-capture.lambda.out
+++ b/1_k/1_lambda/lesson_5/tests/closed-variable-capture.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  lambda y . ( ( lambda x . lambda y . ( x y ) ) y ) ~> .
+  lambda y . ( ( lambda x . lambda y . ( x y ) ) y ) ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_5/tests/free-variable-capture.lambda.out b/1_k/1_lambda/lesson_5/tests/free-variable-capture.lambda.out
index ea4c74bd..556ded24 100644
--- a/1_k/1_lambda/lesson_5/tests/free-variable-capture.lambda.out
+++ b/1_k/1_lambda/lesson_5/tests/free-variable-capture.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  a y ~> .
+  a y ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_5/tests/identity.lambda.out b/1_k/1_lambda/lesson_5/tests/identity.lambda.out
index 46c620ac..9476ee41 100644
--- a/1_k/1_lambda/lesson_5/tests/identity.lambda.out
+++ b/1_k/1_lambda/lesson_5/tests/identity.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  lambda x . x ~> .
+  lambda x . x ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_6/tests/arithmetic.lambda.out b/1_k/1_lambda/lesson_6/tests/arithmetic.lambda.out
index 12360172..97f10093 100644
--- a/1_k/1_lambda/lesson_6/tests/arithmetic.lambda.out
+++ b/1_k/1_lambda/lesson_6/tests/arithmetic.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  true ~> .
+  true ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_6/tests/closed-variable-capture.lambda.out b/1_k/1_lambda/lesson_6/tests/closed-variable-capture.lambda.out
index c79d05f4..4134bc85 100644
--- a/1_k/1_lambda/lesson_6/tests/closed-variable-capture.lambda.out
+++ b/1_k/1_lambda/lesson_6/tests/closed-variable-capture.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  lambda y . ( ( lambda x . lambda y . ( x y ) ) y ) ~> .
+  lambda y . ( ( lambda x . lambda y . ( x y ) ) y ) ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_6/tests/free-variable-capture.lambda.out b/1_k/1_lambda/lesson_6/tests/free-variable-capture.lambda.out
index ea4c74bd..556ded24 100644
--- a/1_k/1_lambda/lesson_6/tests/free-variable-capture.lambda.out
+++ b/1_k/1_lambda/lesson_6/tests/free-variable-capture.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  a y ~> .
+  a y ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_6/tests/identity.lambda.out b/1_k/1_lambda/lesson_6/tests/identity.lambda.out
index 46c620ac..9476ee41 100644
--- a/1_k/1_lambda/lesson_6/tests/identity.lambda.out
+++ b/1_k/1_lambda/lesson_6/tests/identity.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  lambda x . x ~> .
+  lambda x . x ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_6/tests/if.lambda.out b/1_k/1_lambda/lesson_6/tests/if.lambda.out
index faedaaaf..1b239a34 100644
--- a/1_k/1_lambda/lesson_6/tests/if.lambda.out
+++ b/1_k/1_lambda/lesson_6/tests/if.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  10 ~> .
+  10 ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_7/tests/arithmetic.lambda.out b/1_k/1_lambda/lesson_7/tests/arithmetic.lambda.out
index 12360172..97f10093 100644
--- a/1_k/1_lambda/lesson_7/tests/arithmetic.lambda.out
+++ b/1_k/1_lambda/lesson_7/tests/arithmetic.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  true ~> .
+  true ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_7/tests/closed-variable-capture.lambda.out b/1_k/1_lambda/lesson_7/tests/closed-variable-capture.lambda.out
index c79d05f4..4134bc85 100644
--- a/1_k/1_lambda/lesson_7/tests/closed-variable-capture.lambda.out
+++ b/1_k/1_lambda/lesson_7/tests/closed-variable-capture.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  lambda y . ( ( lambda x . lambda y . ( x y ) ) y ) ~> .
+  lambda y . ( ( lambda x . lambda y . ( x y ) ) y ) ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_7/tests/factorial-let-fix.lambda.out b/1_k/1_lambda/lesson_7/tests/factorial-let-fix.lambda.out
index 31643d70..c36a0d86 100644
--- a/1_k/1_lambda/lesson_7/tests/factorial-let-fix.lambda.out
+++ b/1_k/1_lambda/lesson_7/tests/factorial-let-fix.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  3628800 ~> .
+  3628800 ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_7/tests/factorial-let.lambda.out b/1_k/1_lambda/lesson_7/tests/factorial-let.lambda.out
index 31643d70..c36a0d86 100644
--- a/1_k/1_lambda/lesson_7/tests/factorial-let.lambda.out
+++ b/1_k/1_lambda/lesson_7/tests/factorial-let.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  3628800 ~> .
+  3628800 ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_7/tests/factorial-letrec.lambda.out b/1_k/1_lambda/lesson_7/tests/factorial-letrec.lambda.out
index 31643d70..c36a0d86 100644
--- a/1_k/1_lambda/lesson_7/tests/factorial-letrec.lambda.out
+++ b/1_k/1_lambda/lesson_7/tests/factorial-letrec.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  3628800 ~> .
+  3628800 ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_7/tests/free-variable-capture.lambda.out b/1_k/1_lambda/lesson_7/tests/free-variable-capture.lambda.out
index ea4c74bd..556ded24 100644
--- a/1_k/1_lambda/lesson_7/tests/free-variable-capture.lambda.out
+++ b/1_k/1_lambda/lesson_7/tests/free-variable-capture.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  a y ~> .
+  a y ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_7/tests/identity.lambda.out b/1_k/1_lambda/lesson_7/tests/identity.lambda.out
index 46c620ac..9476ee41 100644
--- a/1_k/1_lambda/lesson_7/tests/identity.lambda.out
+++ b/1_k/1_lambda/lesson_7/tests/identity.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  lambda x . x ~> .
+  lambda x . x ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_7/tests/if.lambda.out b/1_k/1_lambda/lesson_7/tests/if.lambda.out
index faedaaaf..1b239a34 100644
--- a/1_k/1_lambda/lesson_7/tests/if.lambda.out
+++ b/1_k/1_lambda/lesson_7/tests/if.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  10 ~> .
+  10 ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_7/tests/lets.lambda.out b/1_k/1_lambda/lesson_7/tests/lets.lambda.out
index 12360172..97f10093 100644
--- a/1_k/1_lambda/lesson_7/tests/lets.lambda.out
+++ b/1_k/1_lambda/lesson_7/tests/lets.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  true ~> .
+  true ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_8/tests/arithmetic.lambda.out b/1_k/1_lambda/lesson_8/tests/arithmetic.lambda.out
index 12360172..97f10093 100644
--- a/1_k/1_lambda/lesson_8/tests/arithmetic.lambda.out
+++ b/1_k/1_lambda/lesson_8/tests/arithmetic.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  true ~> .
+  true ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_8/tests/closed-variable-capture.lambda.out b/1_k/1_lambda/lesson_8/tests/closed-variable-capture.lambda.out
index c79d05f4..4134bc85 100644
--- a/1_k/1_lambda/lesson_8/tests/closed-variable-capture.lambda.out
+++ b/1_k/1_lambda/lesson_8/tests/closed-variable-capture.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  lambda y . ( ( lambda x . lambda y . ( x y ) ) y ) ~> .
+  lambda y . ( ( lambda x . lambda y . ( x y ) ) y ) ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_8/tests/factorial-let-fix.lambda.out b/1_k/1_lambda/lesson_8/tests/factorial-let-fix.lambda.out
index 31643d70..c36a0d86 100644
--- a/1_k/1_lambda/lesson_8/tests/factorial-let-fix.lambda.out
+++ b/1_k/1_lambda/lesson_8/tests/factorial-let-fix.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  3628800 ~> .
+  3628800 ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_8/tests/factorial-let.lambda.out b/1_k/1_lambda/lesson_8/tests/factorial-let.lambda.out
index 31643d70..c36a0d86 100644
--- a/1_k/1_lambda/lesson_8/tests/factorial-let.lambda.out
+++ b/1_k/1_lambda/lesson_8/tests/factorial-let.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  3628800 ~> .
+  3628800 ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_8/tests/factorial-letrec.lambda.out b/1_k/1_lambda/lesson_8/tests/factorial-letrec.lambda.out
index 31643d70..c36a0d86 100644
--- a/1_k/1_lambda/lesson_8/tests/factorial-letrec.lambda.out
+++ b/1_k/1_lambda/lesson_8/tests/factorial-letrec.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  3628800 ~> .
+  3628800 ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_8/tests/fibbo.lambda.out b/1_k/1_lambda/lesson_8/tests/fibbo.lambda.out
index 7b3823ba..dac83548 100644
--- a/1_k/1_lambda/lesson_8/tests/fibbo.lambda.out
+++ b/1_k/1_lambda/lesson_8/tests/fibbo.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  13 ~> .
+  13 ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_8/tests/free-variable-capture.lambda.out b/1_k/1_lambda/lesson_8/tests/free-variable-capture.lambda.out
index ea4c74bd..556ded24 100644
--- a/1_k/1_lambda/lesson_8/tests/free-variable-capture.lambda.out
+++ b/1_k/1_lambda/lesson_8/tests/free-variable-capture.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  a y ~> .
+  a y ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_8/tests/identity.lambda.out b/1_k/1_lambda/lesson_8/tests/identity.lambda.out
index 46c620ac..9476ee41 100644
--- a/1_k/1_lambda/lesson_8/tests/identity.lambda.out
+++ b/1_k/1_lambda/lesson_8/tests/identity.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  lambda x . x ~> .
+  lambda x . x ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_8/tests/if.lambda.out b/1_k/1_lambda/lesson_8/tests/if.lambda.out
index faedaaaf..1b239a34 100644
--- a/1_k/1_lambda/lesson_8/tests/if.lambda.out
+++ b/1_k/1_lambda/lesson_8/tests/if.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  10 ~> .
+  10 ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_8/tests/lets.lambda.out b/1_k/1_lambda/lesson_8/tests/lets.lambda.out
index 12360172..97f10093 100644
--- a/1_k/1_lambda/lesson_8/tests/lets.lambda.out
+++ b/1_k/1_lambda/lesson_8/tests/lets.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  true ~> .
+  true ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_9/tests/arithmetic.lambda.out b/1_k/1_lambda/lesson_9/tests/arithmetic.lambda.out
index 12360172..97f10093 100644
--- a/1_k/1_lambda/lesson_9/tests/arithmetic.lambda.out
+++ b/1_k/1_lambda/lesson_9/tests/arithmetic.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  true ~> .
+  true ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_9/tests/closed-variable-capture.lambda.out b/1_k/1_lambda/lesson_9/tests/closed-variable-capture.lambda.out
index c79d05f4..4134bc85 100644
--- a/1_k/1_lambda/lesson_9/tests/closed-variable-capture.lambda.out
+++ b/1_k/1_lambda/lesson_9/tests/closed-variable-capture.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  lambda y . ( ( lambda x . lambda y . ( x y ) ) y ) ~> .
+  lambda y . ( ( lambda x . lambda y . ( x y ) ) y ) ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_9/tests/factorial-let-fix.lambda.out b/1_k/1_lambda/lesson_9/tests/factorial-let-fix.lambda.out
index 31643d70..c36a0d86 100644
--- a/1_k/1_lambda/lesson_9/tests/factorial-let-fix.lambda.out
+++ b/1_k/1_lambda/lesson_9/tests/factorial-let-fix.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  3628800 ~> .
+  3628800 ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_9/tests/factorial-let.lambda.out b/1_k/1_lambda/lesson_9/tests/factorial-let.lambda.out
index 31643d70..c36a0d86 100644
--- a/1_k/1_lambda/lesson_9/tests/factorial-let.lambda.out
+++ b/1_k/1_lambda/lesson_9/tests/factorial-let.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  3628800 ~> .
+  3628800 ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_9/tests/factorial-letrec.lambda.out b/1_k/1_lambda/lesson_9/tests/factorial-letrec.lambda.out
index 31643d70..c36a0d86 100644
--- a/1_k/1_lambda/lesson_9/tests/factorial-letrec.lambda.out
+++ b/1_k/1_lambda/lesson_9/tests/factorial-letrec.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  3628800 ~> .
+  3628800 ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_9/tests/fibbo-church.lambda.out b/1_k/1_lambda/lesson_9/tests/fibbo-church.lambda.out
index 7b3823ba..dac83548 100644
--- a/1_k/1_lambda/lesson_9/tests/fibbo-church.lambda.out
+++ b/1_k/1_lambda/lesson_9/tests/fibbo-church.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  13 ~> .
+  13 ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_9/tests/fibbo.lambda.out b/1_k/1_lambda/lesson_9/tests/fibbo.lambda.out
index 7b3823ba..dac83548 100644
--- a/1_k/1_lambda/lesson_9/tests/fibbo.lambda.out
+++ b/1_k/1_lambda/lesson_9/tests/fibbo.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  13 ~> .
+  13 ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_9/tests/free-variable-capture.lambda.out b/1_k/1_lambda/lesson_9/tests/free-variable-capture.lambda.out
index ea4c74bd..556ded24 100644
--- a/1_k/1_lambda/lesson_9/tests/free-variable-capture.lambda.out
+++ b/1_k/1_lambda/lesson_9/tests/free-variable-capture.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  a y ~> .
+  a y ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_9/tests/identity.lambda.out b/1_k/1_lambda/lesson_9/tests/identity.lambda.out
index 46c620ac..9476ee41 100644
--- a/1_k/1_lambda/lesson_9/tests/identity.lambda.out
+++ b/1_k/1_lambda/lesson_9/tests/identity.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  lambda x . x ~> .
+  lambda x . x ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_9/tests/if.lambda.out b/1_k/1_lambda/lesson_9/tests/if.lambda.out
index faedaaaf..1b239a34 100644
--- a/1_k/1_lambda/lesson_9/tests/if.lambda.out
+++ b/1_k/1_lambda/lesson_9/tests/if.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  10 ~> .
+  10 ~> .K
 </k>
diff --git a/1_k/1_lambda/lesson_9/tests/lets.lambda.out b/1_k/1_lambda/lesson_9/tests/lets.lambda.out
index 12360172..97f10093 100644
--- a/1_k/1_lambda/lesson_9/tests/lets.lambda.out
+++ b/1_k/1_lambda/lesson_9/tests/lets.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  true ~> .
+  true ~> .K
 </k>
diff --git a/1_k/2_imp/lesson_1/tests/collatz.imp.out b/1_k/2_imp/lesson_1/tests/collatz.imp.out
index 88e74d91..50b0ed54 100644
--- a/1_k/2_imp/lesson_1/tests/collatz.imp.out
+++ b/1_k/2_imp/lesson_1/tests/collatz.imp.out
@@ -1,3 +1,3 @@
 <k>
-  int m , n , q , r , s , .Ids ; m = 10 ; while ( ! m <= 2 ) { n = m ; m = m + - 1 ; while ( ! n <= 1 ) { s = s + 1 ; q = n / 2 ; r = q + q + 1 ; if ( r <= n ) { n = n + n + n + 1 ; } else { n = q ; } } } ~> .
+  int m , n , q , r , s , .Ids ; m = 10 ; while ( ! m <= 2 ) { n = m ; m = m + - 1 ; while ( ! n <= 1 ) { s = s + 1 ; q = n / 2 ; r = q + q + 1 ; if ( r <= n ) { n = n + n + n + 1 ; } else { n = q ; } } } ~> .K
 </k>
diff --git a/1_k/2_imp/lesson_1/tests/primes.imp.out b/1_k/2_imp/lesson_1/tests/primes.imp.out
index 393dffbb..f9f5fc23 100644
--- a/1_k/2_imp/lesson_1/tests/primes.imp.out
+++ b/1_k/2_imp/lesson_1/tests/primes.imp.out
@@ -1,3 +1,3 @@
 <k>
-  int i , m , n , q , r , s , t , x , y , z , .Ids ; m = 10 ; n = 2 ; while ( n <= m ) { i = 2 ; q = n / i ; t = 1 ; while ( i <= q && 1 <= t ) { x = i ; y = q ; z = 0 ; while ( ! x <= 0 ) { q = x / 2 ; r = q + q + 1 ; if ( r <= x ) { z = z + y ; } else { } x = q ; y = y + y ; } if ( n <= z ) { t = 0 ; } else { i = i + 1 ; q = n / i ; } } if ( 1 <= t ) { s = s + 1 ; } else { } n = n + 1 ; } ~> .
+  int i , m , n , q , r , s , t , x , y , z , .Ids ; m = 10 ; n = 2 ; while ( n <= m ) { i = 2 ; q = n / i ; t = 1 ; while ( i <= q && 1 <= t ) { x = i ; y = q ; z = 0 ; while ( ! x <= 0 ) { q = x / 2 ; r = q + q + 1 ; if ( r <= x ) { z = z + y ; } else { } x = q ; y = y + y ; } if ( n <= z ) { t = 0 ; } else { i = i + 1 ; q = n / i ; } } if ( 1 <= t ) { s = s + 1 ; } else { } n = n + 1 ; } ~> .K
 </k>
diff --git a/1_k/2_imp/lesson_1/tests/sum.imp.out b/1_k/2_imp/lesson_1/tests/sum.imp.out
index e4012cab..5d3e4c9a 100644
--- a/1_k/2_imp/lesson_1/tests/sum.imp.out
+++ b/1_k/2_imp/lesson_1/tests/sum.imp.out
@@ -1,3 +1,3 @@
 <k>
-  int n , sum , .Ids ; n = 100 ; sum = 0 ; while ( ! n <= 0 ) { sum = sum + n ; n = n + - 1 ; } ~> .
+  int n , sum , .Ids ; n = 100 ; sum = 0 ; while ( ! n <= 0 ) { sum = sum + n ; n = n + - 1 ; } ~> .K
 </k>
diff --git a/1_k/2_imp/lesson_2/tests/collatz.imp.out b/1_k/2_imp/lesson_2/tests/collatz.imp.out
index 0b8674ca..e2accbf9 100644
--- a/1_k/2_imp/lesson_2/tests/collatz.imp.out
+++ b/1_k/2_imp/lesson_2/tests/collatz.imp.out
@@ -1,6 +1,6 @@
 <T>
   <k>
-    int m , n , q , r , s , .Ids ; m = 10 ; while ( ! m <= 2 ) { n = m ; m = m + - 1 ; while ( ! n <= 1 ) { s = s + 1 ; q = n / 2 ; r = q + q + 1 ; if ( r <= n ) { n = n + n + n + 1 ; } else { n = q ; } } } ~> .
+    int m , n , q , r , s , .Ids ; m = 10 ; while ( ! m <= 2 ) { n = m ; m = m + - 1 ; while ( ! n <= 1 ) { s = s + 1 ; q = n / 2 ; r = q + q + 1 ; if ( r <= n ) { n = n + n + n + 1 ; } else { n = q ; } } } ~> .K
   </k>
   <state>
     .Map
diff --git a/1_k/2_imp/lesson_2/tests/primes.imp.out b/1_k/2_imp/lesson_2/tests/primes.imp.out
index b975be1a..54f1009e 100644
--- a/1_k/2_imp/lesson_2/tests/primes.imp.out
+++ b/1_k/2_imp/lesson_2/tests/primes.imp.out
@@ -1,6 +1,6 @@
 <T>
   <k>
-    int i , m , n , q , r , s , t , x , y , z , .Ids ; m = 10 ; n = 2 ; while ( n <= m ) { i = 2 ; q = n / i ; t = 1 ; while ( i <= q && 1 <= t ) { x = i ; y = q ; z = 0 ; while ( ! x <= 0 ) { q = x / 2 ; r = q + q + 1 ; if ( r <= x ) { z = z + y ; } else { } x = q ; y = y + y ; } if ( n <= z ) { t = 0 ; } else { i = i + 1 ; q = n / i ; } } if ( 1 <= t ) { s = s + 1 ; } else { } n = n + 1 ; } ~> .
+    int i , m , n , q , r , s , t , x , y , z , .Ids ; m = 10 ; n = 2 ; while ( n <= m ) { i = 2 ; q = n / i ; t = 1 ; while ( i <= q && 1 <= t ) { x = i ; y = q ; z = 0 ; while ( ! x <= 0 ) { q = x / 2 ; r = q + q + 1 ; if ( r <= x ) { z = z + y ; } else { } x = q ; y = y + y ; } if ( n <= z ) { t = 0 ; } else { i = i + 1 ; q = n / i ; } } if ( 1 <= t ) { s = s + 1 ; } else { } n = n + 1 ; } ~> .K
   </k>
   <state>
     .Map
diff --git a/1_k/2_imp/lesson_2/tests/sum.imp.out b/1_k/2_imp/lesson_2/tests/sum.imp.out
index 80a08851..0eb6ad80 100644
--- a/1_k/2_imp/lesson_2/tests/sum.imp.out
+++ b/1_k/2_imp/lesson_2/tests/sum.imp.out
@@ -1,6 +1,6 @@
 <T>
   <k>
-    int n , sum , .Ids ; n = 100 ; sum = 0 ; while ( ! n <= 0 ) { sum = sum + n ; n = n + - 1 ; } ~> .
+    int n , sum , .Ids ; n = 100 ; sum = 0 ; while ( ! n <= 0 ) { sum = sum + n ; n = n + - 1 ; } ~> .K
   </k>
   <state>
     .Map
diff --git a/1_k/2_imp/lesson_3/tests/collatz.imp.out b/1_k/2_imp/lesson_3/tests/collatz.imp.out
index 0b8674ca..e2accbf9 100644
--- a/1_k/2_imp/lesson_3/tests/collatz.imp.out
+++ b/1_k/2_imp/lesson_3/tests/collatz.imp.out
@@ -1,6 +1,6 @@
 <T>
   <k>
-    int m , n , q , r , s , .Ids ; m = 10 ; while ( ! m <= 2 ) { n = m ; m = m + - 1 ; while ( ! n <= 1 ) { s = s + 1 ; q = n / 2 ; r = q + q + 1 ; if ( r <= n ) { n = n + n + n + 1 ; } else { n = q ; } } } ~> .
+    int m , n , q , r , s , .Ids ; m = 10 ; while ( ! m <= 2 ) { n = m ; m = m + - 1 ; while ( ! n <= 1 ) { s = s + 1 ; q = n / 2 ; r = q + q + 1 ; if ( r <= n ) { n = n + n + n + 1 ; } else { n = q ; } } } ~> .K
   </k>
   <state>
     .Map
diff --git a/1_k/2_imp/lesson_3/tests/primes.imp.out b/1_k/2_imp/lesson_3/tests/primes.imp.out
index b975be1a..54f1009e 100644
--- a/1_k/2_imp/lesson_3/tests/primes.imp.out
+++ b/1_k/2_imp/lesson_3/tests/primes.imp.out
@@ -1,6 +1,6 @@
 <T>
   <k>
-    int i , m , n , q , r , s , t , x , y , z , .Ids ; m = 10 ; n = 2 ; while ( n <= m ) { i = 2 ; q = n / i ; t = 1 ; while ( i <= q && 1 <= t ) { x = i ; y = q ; z = 0 ; while ( ! x <= 0 ) { q = x / 2 ; r = q + q + 1 ; if ( r <= x ) { z = z + y ; } else { } x = q ; y = y + y ; } if ( n <= z ) { t = 0 ; } else { i = i + 1 ; q = n / i ; } } if ( 1 <= t ) { s = s + 1 ; } else { } n = n + 1 ; } ~> .
+    int i , m , n , q , r , s , t , x , y , z , .Ids ; m = 10 ; n = 2 ; while ( n <= m ) { i = 2 ; q = n / i ; t = 1 ; while ( i <= q && 1 <= t ) { x = i ; y = q ; z = 0 ; while ( ! x <= 0 ) { q = x / 2 ; r = q + q + 1 ; if ( r <= x ) { z = z + y ; } else { } x = q ; y = y + y ; } if ( n <= z ) { t = 0 ; } else { i = i + 1 ; q = n / i ; } } if ( 1 <= t ) { s = s + 1 ; } else { } n = n + 1 ; } ~> .K
   </k>
   <state>
     .Map
diff --git a/1_k/2_imp/lesson_3/tests/sum.imp.out b/1_k/2_imp/lesson_3/tests/sum.imp.out
index 80a08851..0eb6ad80 100644
--- a/1_k/2_imp/lesson_3/tests/sum.imp.out
+++ b/1_k/2_imp/lesson_3/tests/sum.imp.out
@@ -1,6 +1,6 @@
 <T>
   <k>
-    int n , sum , .Ids ; n = 100 ; sum = 0 ; while ( ! n <= 0 ) { sum = sum + n ; n = n + - 1 ; } ~> .
+    int n , sum , .Ids ; n = 100 ; sum = 0 ; while ( ! n <= 0 ) { sum = sum + n ; n = n + - 1 ; } ~> .K
   </k>
   <state>
     .Map
diff --git a/1_k/2_imp/lesson_4/tests/collatz.imp.out b/1_k/2_imp/lesson_4/tests/collatz.imp.out
index 4e77a353..746da717 100644
--- a/1_k/2_imp/lesson_4/tests/collatz.imp.out
+++ b/1_k/2_imp/lesson_4/tests/collatz.imp.out
@@ -1,6 +1,6 @@
 <T>
   <k>
-    .
+    .K
   </k>
   <state>
     m |-> 2
diff --git a/1_k/2_imp/lesson_4/tests/primes.imp.out b/1_k/2_imp/lesson_4/tests/primes.imp.out
index dc1326e5..702afd61 100644
--- a/1_k/2_imp/lesson_4/tests/primes.imp.out
+++ b/1_k/2_imp/lesson_4/tests/primes.imp.out
@@ -1,6 +1,6 @@
 <T>
   <k>
-    .
+    .K
   </k>
   <state>
     i |-> 2
diff --git a/1_k/2_imp/lesson_4/tests/sum.imp.out b/1_k/2_imp/lesson_4/tests/sum.imp.out
index f72ab68a..d6373fd2 100644
--- a/1_k/2_imp/lesson_4/tests/sum.imp.out
+++ b/1_k/2_imp/lesson_4/tests/sum.imp.out
@@ -1,6 +1,6 @@
 <T>
   <k>
-    .
+    .K
   </k>
   <state>
     n |-> 0
diff --git a/1_k/2_imp/lesson_5/tests/collatz.imp.out b/1_k/2_imp/lesson_5/tests/collatz.imp.out
index 4e77a353..746da717 100644
--- a/1_k/2_imp/lesson_5/tests/collatz.imp.out
+++ b/1_k/2_imp/lesson_5/tests/collatz.imp.out
@@ -1,6 +1,6 @@
 <T>
   <k>
-    .
+    .K
   </k>
   <state>
     m |-> 2
diff --git a/1_k/2_imp/lesson_5/tests/primes.imp.out b/1_k/2_imp/lesson_5/tests/primes.imp.out
index dc1326e5..702afd61 100644
--- a/1_k/2_imp/lesson_5/tests/primes.imp.out
+++ b/1_k/2_imp/lesson_5/tests/primes.imp.out
@@ -1,6 +1,6 @@
 <T>
   <k>
-    .
+    .K
   </k>
   <state>
     i |-> 2
diff --git a/1_k/2_imp/lesson_5/tests/sum.imp.out b/1_k/2_imp/lesson_5/tests/sum.imp.out
index f72ab68a..d6373fd2 100644
--- a/1_k/2_imp/lesson_5/tests/sum.imp.out
+++ b/1_k/2_imp/lesson_5/tests/sum.imp.out
@@ -1,6 +1,6 @@
 <T>
   <k>
-    .
+    .K
   </k>
   <state>
     n |-> 0
diff --git a/1_k/3_lambda++/lesson_1/tests/arithmetic.lambda.out b/1_k/3_lambda++/lesson_1/tests/arithmetic.lambda.out
index 12360172..97f10093 100644
--- a/1_k/3_lambda++/lesson_1/tests/arithmetic.lambda.out
+++ b/1_k/3_lambda++/lesson_1/tests/arithmetic.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  true ~> .
+  true ~> .K
 </k>
diff --git a/1_k/3_lambda++/lesson_1/tests/callcc-jump.lambda.out b/1_k/3_lambda++/lesson_1/tests/callcc-jump.lambda.out
index eb2385c1..db4e6bd8 100644
--- a/1_k/3_lambda++/lesson_1/tests/callcc-jump.lambda.out
+++ b/1_k/3_lambda++/lesson_1/tests/callcc-jump.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  15 ~> .
+  15 ~> .K
 </k>
diff --git a/1_k/3_lambda++/lesson_1/tests/callcc-not-jump.lambda.out b/1_k/3_lambda++/lesson_1/tests/callcc-not-jump.lambda.out
index 3f513e00..c05155d6 100644
--- a/1_k/3_lambda++/lesson_1/tests/callcc-not-jump.lambda.out
+++ b/1_k/3_lambda++/lesson_1/tests/callcc-not-jump.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  17 ~> .
+  17 ~> .K
 </k>
diff --git a/1_k/3_lambda++/lesson_1/tests/callcc-return.lambda.out b/1_k/3_lambda++/lesson_1/tests/callcc-return.lambda.out
index 63d0524f..36e7b68b 100644
--- a/1_k/3_lambda++/lesson_1/tests/callcc-return.lambda.out
+++ b/1_k/3_lambda++/lesson_1/tests/callcc-return.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  1 ~> .
+  1 ~> .K
 </k>
diff --git a/1_k/3_lambda++/lesson_1/tests/callcc-with-let.lambda.out b/1_k/3_lambda++/lesson_1/tests/callcc-with-let.lambda.out
index 9051ba6f..d0e47e5d 100644
--- a/1_k/3_lambda++/lesson_1/tests/callcc-with-let.lambda.out
+++ b/1_k/3_lambda++/lesson_1/tests/callcc-with-let.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  32 ~> .
+  32 ~> .K
 </k>
diff --git a/1_k/3_lambda++/lesson_1/tests/closed-variable-capture.lambda.out b/1_k/3_lambda++/lesson_1/tests/closed-variable-capture.lambda.out
index 7cb2c2a2..b4b7c6bc 100644
--- a/1_k/3_lambda++/lesson_1/tests/closed-variable-capture.lambda.out
+++ b/1_k/3_lambda++/lesson_1/tests/closed-variable-capture.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  lambda y . ( ( lambda x . lambda y0 . ( x y0 ) ) y ) ~> .
+  lambda y . ( ( lambda x . lambda y0 . ( x y0 ) ) y ) ~> .K
 </k>
diff --git a/1_k/3_lambda++/lesson_1/tests/factorial-let-fix.lambda.out b/1_k/3_lambda++/lesson_1/tests/factorial-let-fix.lambda.out
index 31643d70..c36a0d86 100644
--- a/1_k/3_lambda++/lesson_1/tests/factorial-let-fix.lambda.out
+++ b/1_k/3_lambda++/lesson_1/tests/factorial-let-fix.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  3628800 ~> .
+  3628800 ~> .K
 </k>
diff --git a/1_k/3_lambda++/lesson_1/tests/factorial-let.lambda.out b/1_k/3_lambda++/lesson_1/tests/factorial-let.lambda.out
index 31643d70..c36a0d86 100644
--- a/1_k/3_lambda++/lesson_1/tests/factorial-let.lambda.out
+++ b/1_k/3_lambda++/lesson_1/tests/factorial-let.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  3628800 ~> .
+  3628800 ~> .K
 </k>
diff --git a/1_k/3_lambda++/lesson_1/tests/factorial-letrec.lambda.out b/1_k/3_lambda++/lesson_1/tests/factorial-letrec.lambda.out
index 31643d70..c36a0d86 100644
--- a/1_k/3_lambda++/lesson_1/tests/factorial-letrec.lambda.out
+++ b/1_k/3_lambda++/lesson_1/tests/factorial-letrec.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  3628800 ~> .
+  3628800 ~> .K
 </k>
diff --git a/1_k/3_lambda++/lesson_1/tests/fibbo.lambda.out b/1_k/3_lambda++/lesson_1/tests/fibbo.lambda.out
index 7b3823ba..dac83548 100644
--- a/1_k/3_lambda++/lesson_1/tests/fibbo.lambda.out
+++ b/1_k/3_lambda++/lesson_1/tests/fibbo.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  13 ~> .
+  13 ~> .K
 </k>
diff --git a/1_k/3_lambda++/lesson_1/tests/free-variable-capture.lambda.out b/1_k/3_lambda++/lesson_1/tests/free-variable-capture.lambda.out
index ea4c74bd..556ded24 100644
--- a/1_k/3_lambda++/lesson_1/tests/free-variable-capture.lambda.out
+++ b/1_k/3_lambda++/lesson_1/tests/free-variable-capture.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  a y ~> .
+  a y ~> .K
 </k>
diff --git a/1_k/3_lambda++/lesson_1/tests/identity.lambda.out b/1_k/3_lambda++/lesson_1/tests/identity.lambda.out
index 46c620ac..9476ee41 100644
--- a/1_k/3_lambda++/lesson_1/tests/identity.lambda.out
+++ b/1_k/3_lambda++/lesson_1/tests/identity.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  lambda x . x ~> .
+  lambda x . x ~> .K
 </k>
diff --git a/1_k/3_lambda++/lesson_1/tests/if.lambda.out b/1_k/3_lambda++/lesson_1/tests/if.lambda.out
index faedaaaf..1b239a34 100644
--- a/1_k/3_lambda++/lesson_1/tests/if.lambda.out
+++ b/1_k/3_lambda++/lesson_1/tests/if.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  10 ~> .
+  10 ~> .K
 </k>
diff --git a/1_k/3_lambda++/lesson_1/tests/lets.lambda.out b/1_k/3_lambda++/lesson_1/tests/lets.lambda.out
index 12360172..97f10093 100644
--- a/1_k/3_lambda++/lesson_1/tests/lets.lambda.out
+++ b/1_k/3_lambda++/lesson_1/tests/lets.lambda.out
@@ -1,3 +1,3 @@
 <k>
-  true ~> .
+  true ~> .K
 </k>
diff --git a/1_k/3_lambda++/lesson_2/tests/closed-variable-capture.lambda.out b/1_k/3_lambda++/lesson_2/tests/closed-variable-capture.lambda.out
index b6bf03fa..370d2457 100644
--- a/1_k/3_lambda++/lesson_2/tests/closed-variable-capture.lambda.out
+++ b/1_k/3_lambda++/lesson_2/tests/closed-variable-capture.lambda.out
@@ -1,5 +1,5 @@
 {
   V:K
 #Equals
-  closure ( x |-> 1 , y , x y ) ~> .
+  closure ( x |-> 1 , y , x y ) ~> .K
 }
diff --git a/1_k/3_lambda++/lesson_2/tests/free-variable-capture.lambda.out b/1_k/3_lambda++/lesson_2/tests/free-variable-capture.lambda.out
index 1611b54b..90350803 100644
--- a/1_k/3_lambda++/lesson_2/tests/free-variable-capture.lambda.out
+++ b/1_k/3_lambda++/lesson_2/tests/free-variable-capture.lambda.out
@@ -1,23 +1,23 @@
   {
     V:K
   #Equals
-    a ~> #freezer___LAMBDA_Exp_Exp_Exp0_ ( ( lambda x . lambda y . x ) y z ~> . ) ~> .
+    a ~> #freezer___LAMBDA_Exp_Exp_Exp0_ ( ( lambda x . lambda y . x ) y z ~> .K ) ~> .K
   }
 #Or
   {
     V:K
   #Equals
-    y ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( closure ( .Map , x , lambda y . x ) ~> . ) ~> #freezer___LAMBDA_Exp_Exp_Exp0_ ( z ~> . ) ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( a ~> . ) ~> .
+    y ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( closure ( .Map , x , lambda y . x ) ~> .K ) ~> #freezer___LAMBDA_Exp_Exp_Exp0_ ( z ~> .K ) ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( a ~> .K ) ~> .K
   }
 #Or
   {
     V:K
   #Equals
-    y ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( lambda x . lambda y . x ~> . ) ~> #freezer___LAMBDA_Exp_Exp_Exp0_ ( z ~> . ) ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( a ~> . ) ~> .
+    y ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( lambda x . lambda y . x ~> .K ) ~> #freezer___LAMBDA_Exp_Exp_Exp0_ ( z ~> .K ) ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( a ~> .K ) ~> .K
   }
 #Or
   {
     V:K
   #Equals
-    z ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( ( lambda x . lambda y . x ) y ~> . ) ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( a ~> . ) ~> .
+    z ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( ( lambda x . lambda y . x ) y ~> .K ) ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( a ~> .K ) ~> .K
   }
diff --git a/1_k/3_lambda++/lesson_2/tests/identity.lambda.out b/1_k/3_lambda++/lesson_2/tests/identity.lambda.out
index 4d5cd5b9..216e622c 100644
--- a/1_k/3_lambda++/lesson_2/tests/identity.lambda.out
+++ b/1_k/3_lambda++/lesson_2/tests/identity.lambda.out
@@ -1,5 +1,5 @@
 {
   V:K
 #Equals
-  closure ( .Map , x , x ) ~> .
+  closure ( .Map , x , x ) ~> .K
 }
diff --git a/1_k/3_lambda++/lesson_3/tests/closed-variable-capture.lambda.out b/1_k/3_lambda++/lesson_3/tests/closed-variable-capture.lambda.out
index b6bf03fa..370d2457 100644
--- a/1_k/3_lambda++/lesson_3/tests/closed-variable-capture.lambda.out
+++ b/1_k/3_lambda++/lesson_3/tests/closed-variable-capture.lambda.out
@@ -1,5 +1,5 @@
 {
   V:K
 #Equals
-  closure ( x |-> 1 , y , x y ) ~> .
+  closure ( x |-> 1 , y , x y ) ~> .K
 }
diff --git a/1_k/3_lambda++/lesson_3/tests/free-variable-capture.lambda.out b/1_k/3_lambda++/lesson_3/tests/free-variable-capture.lambda.out
index 1611b54b..90350803 100644
--- a/1_k/3_lambda++/lesson_3/tests/free-variable-capture.lambda.out
+++ b/1_k/3_lambda++/lesson_3/tests/free-variable-capture.lambda.out
@@ -1,23 +1,23 @@
   {
     V:K
   #Equals
-    a ~> #freezer___LAMBDA_Exp_Exp_Exp0_ ( ( lambda x . lambda y . x ) y z ~> . ) ~> .
+    a ~> #freezer___LAMBDA_Exp_Exp_Exp0_ ( ( lambda x . lambda y . x ) y z ~> .K ) ~> .K
   }
 #Or
   {
     V:K
   #Equals
-    y ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( closure ( .Map , x , lambda y . x ) ~> . ) ~> #freezer___LAMBDA_Exp_Exp_Exp0_ ( z ~> . ) ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( a ~> . ) ~> .
+    y ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( closure ( .Map , x , lambda y . x ) ~> .K ) ~> #freezer___LAMBDA_Exp_Exp_Exp0_ ( z ~> .K ) ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( a ~> .K ) ~> .K
   }
 #Or
   {
     V:K
   #Equals
-    y ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( lambda x . lambda y . x ~> . ) ~> #freezer___LAMBDA_Exp_Exp_Exp0_ ( z ~> . ) ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( a ~> . ) ~> .
+    y ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( lambda x . lambda y . x ~> .K ) ~> #freezer___LAMBDA_Exp_Exp_Exp0_ ( z ~> .K ) ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( a ~> .K ) ~> .K
   }
 #Or
   {
     V:K
   #Equals
-    z ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( ( lambda x . lambda y . x ) y ~> . ) ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( a ~> . ) ~> .
+    z ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( ( lambda x . lambda y . x ) y ~> .K ) ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( a ~> .K ) ~> .K
   }
diff --git a/1_k/3_lambda++/lesson_3/tests/identity.lambda.out b/1_k/3_lambda++/lesson_3/tests/identity.lambda.out
index 4d5cd5b9..216e622c 100644
--- a/1_k/3_lambda++/lesson_3/tests/identity.lambda.out
+++ b/1_k/3_lambda++/lesson_3/tests/identity.lambda.out
@@ -1,5 +1,5 @@
 {
   V:K
 #Equals
-  closure ( .Map , x , x ) ~> .
+  closure ( .Map , x , x ) ~> .K
 }
diff --git a/1_k/3_lambda++/lesson_4/tests/callcc-env1.lambda.out b/1_k/3_lambda++/lesson_4/tests/callcc-env1.lambda.out
index 844768f8..4272b3ea 100644
--- a/1_k/3_lambda++/lesson_4/tests/callcc-env1.lambda.out
+++ b/1_k/3_lambda++/lesson_4/tests/callcc-env1.lambda.out
@@ -1,11 +1,11 @@
   {
     V:K
   #Equals
-    3 ~> .
+    3 ~> .K
   }
 #Or
   {
     V:K
   #Equals
-    4 ~> .
+    4 ~> .K
   }
diff --git a/1_k/3_lambda++/lesson_4/tests/callcc-env2.lambda.out b/1_k/3_lambda++/lesson_4/tests/callcc-env2.lambda.out
index 844768f8..4272b3ea 100644
--- a/1_k/3_lambda++/lesson_4/tests/callcc-env2.lambda.out
+++ b/1_k/3_lambda++/lesson_4/tests/callcc-env2.lambda.out
@@ -1,11 +1,11 @@
   {
     V:K
   #Equals
-    3 ~> .
+    3 ~> .K
   }
 #Or
   {
     V:K
   #Equals
-    4 ~> .
+    4 ~> .K
   }
diff --git a/1_k/3_lambda++/lesson_4/tests/callcc-with-let.lambda.out b/1_k/3_lambda++/lesson_4/tests/callcc-with-let.lambda.out
index 4a781c72..471a5c06 100644
--- a/1_k/3_lambda++/lesson_4/tests/callcc-with-let.lambda.out
+++ b/1_k/3_lambda++/lesson_4/tests/callcc-with-let.lambda.out
@@ -1,11 +1,11 @@
   {
     V:K
   #Equals
-    32 ~> .
+    32 ~> .K
   }
 #Or
   {
     V:K
   #Equals
-    33 ~> .
+    33 ~> .K
   }
diff --git a/1_k/3_lambda++/lesson_4/tests/closed-variable-capture.lambda.out b/1_k/3_lambda++/lesson_4/tests/closed-variable-capture.lambda.out
index b6bf03fa..370d2457 100644
--- a/1_k/3_lambda++/lesson_4/tests/closed-variable-capture.lambda.out
+++ b/1_k/3_lambda++/lesson_4/tests/closed-variable-capture.lambda.out
@@ -1,5 +1,5 @@
 {
   V:K
 #Equals
-  closure ( x |-> 1 , y , x y ) ~> .
+  closure ( x |-> 1 , y , x y ) ~> .K
 }
diff --git a/1_k/3_lambda++/lesson_4/tests/free-variable-capture.lambda.out b/1_k/3_lambda++/lesson_4/tests/free-variable-capture.lambda.out
index 1611b54b..90350803 100644
--- a/1_k/3_lambda++/lesson_4/tests/free-variable-capture.lambda.out
+++ b/1_k/3_lambda++/lesson_4/tests/free-variable-capture.lambda.out
@@ -1,23 +1,23 @@
   {
     V:K
   #Equals
-    a ~> #freezer___LAMBDA_Exp_Exp_Exp0_ ( ( lambda x . lambda y . x ) y z ~> . ) ~> .
+    a ~> #freezer___LAMBDA_Exp_Exp_Exp0_ ( ( lambda x . lambda y . x ) y z ~> .K ) ~> .K
   }
 #Or
   {
     V:K
   #Equals
-    y ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( closure ( .Map , x , lambda y . x ) ~> . ) ~> #freezer___LAMBDA_Exp_Exp_Exp0_ ( z ~> . ) ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( a ~> . ) ~> .
+    y ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( closure ( .Map , x , lambda y . x ) ~> .K ) ~> #freezer___LAMBDA_Exp_Exp_Exp0_ ( z ~> .K ) ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( a ~> .K ) ~> .K
   }
 #Or
   {
     V:K
   #Equals
-    y ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( lambda x . lambda y . x ~> . ) ~> #freezer___LAMBDA_Exp_Exp_Exp0_ ( z ~> . ) ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( a ~> . ) ~> .
+    y ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( lambda x . lambda y . x ~> .K ) ~> #freezer___LAMBDA_Exp_Exp_Exp0_ ( z ~> .K ) ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( a ~> .K ) ~> .K
   }
 #Or
   {
     V:K
   #Equals
-    z ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( ( lambda x . lambda y . x ) y ~> . ) ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( a ~> . ) ~> .
+    z ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( ( lambda x . lambda y . x ) y ~> .K ) ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( a ~> .K ) ~> .K
   }
diff --git a/1_k/3_lambda++/lesson_4/tests/identity.lambda.out b/1_k/3_lambda++/lesson_4/tests/identity.lambda.out
index 4d5cd5b9..216e622c 100644
--- a/1_k/3_lambda++/lesson_4/tests/identity.lambda.out
+++ b/1_k/3_lambda++/lesson_4/tests/identity.lambda.out
@@ -1,5 +1,5 @@
 {
   V:K
 #Equals
-  closure ( .Map , x , x ) ~> .
+  closure ( .Map , x , x ) ~> .K
 }
diff --git a/1_k/3_lambda++/lesson_5/tests/deterministic/factorial-let-fix.lambda.out b/1_k/3_lambda++/lesson_5/tests/deterministic/factorial-let-fix.lambda.out
index 1c843187..5522f66a 100644
--- a/1_k/3_lambda++/lesson_5/tests/deterministic/factorial-let-fix.lambda.out
+++ b/1_k/3_lambda++/lesson_5/tests/deterministic/factorial-let-fix.lambda.out
@@ -1,5 +1,5 @@
 {
   V:K
 #Equals
-  3628800 ~> .
+  3628800 ~> .K
 }
diff --git a/1_k/3_lambda++/lesson_5/tests/deterministic/factorial-let.lambda.out b/1_k/3_lambda++/lesson_5/tests/deterministic/factorial-let.lambda.out
index 1c843187..5522f66a 100644
--- a/1_k/3_lambda++/lesson_5/tests/deterministic/factorial-let.lambda.out
+++ b/1_k/3_lambda++/lesson_5/tests/deterministic/factorial-let.lambda.out
@@ -1,5 +1,5 @@
 {
   V:K
 #Equals
-  3628800 ~> .
+  3628800 ~> .K
 }
diff --git a/1_k/3_lambda++/lesson_5/tests/deterministic/factorial-letrec.lambda.out b/1_k/3_lambda++/lesson_5/tests/deterministic/factorial-letrec.lambda.out
index 1c843187..5522f66a 100644
--- a/1_k/3_lambda++/lesson_5/tests/deterministic/factorial-letrec.lambda.out
+++ b/1_k/3_lambda++/lesson_5/tests/deterministic/factorial-letrec.lambda.out
@@ -1,5 +1,5 @@
 {
   V:K
 #Equals
-  3628800 ~> .
+  3628800 ~> .K
 }
diff --git a/1_k/3_lambda++/lesson_5/tests/deterministic/fibbo.lambda.out b/1_k/3_lambda++/lesson_5/tests/deterministic/fibbo.lambda.out
index a7028cde..e4b5bd52 100644
--- a/1_k/3_lambda++/lesson_5/tests/deterministic/fibbo.lambda.out
+++ b/1_k/3_lambda++/lesson_5/tests/deterministic/fibbo.lambda.out
@@ -1,5 +1,5 @@
 {
   V:K
 #Equals
-  13 ~> .
+  13 ~> .K
 }
diff --git a/1_k/3_lambda++/lesson_5/tests/nondeterministic/arithmetic.lambda.out b/1_k/3_lambda++/lesson_5/tests/nondeterministic/arithmetic.lambda.out
index a01c03d1..cbb93410 100644
--- a/1_k/3_lambda++/lesson_5/tests/nondeterministic/arithmetic.lambda.out
+++ b/1_k/3_lambda++/lesson_5/tests/nondeterministic/arithmetic.lambda.out
@@ -1,5 +1,5 @@
 {
   V:K
 #Equals
-  true ~> .
+  true ~> .K
 }
diff --git a/1_k/3_lambda++/lesson_5/tests/nondeterministic/callcc-env1.lambda.out b/1_k/3_lambda++/lesson_5/tests/nondeterministic/callcc-env1.lambda.out
index 0d1534ce..32ce768f 100644
--- a/1_k/3_lambda++/lesson_5/tests/nondeterministic/callcc-env1.lambda.out
+++ b/1_k/3_lambda++/lesson_5/tests/nondeterministic/callcc-env1.lambda.out
@@ -1,5 +1,5 @@
 {
   V:K
 #Equals
-  3 ~> .
+  3 ~> .K
 }
diff --git a/1_k/3_lambda++/lesson_5/tests/nondeterministic/callcc-env2.lambda.out b/1_k/3_lambda++/lesson_5/tests/nondeterministic/callcc-env2.lambda.out
index 0d1534ce..32ce768f 100644
--- a/1_k/3_lambda++/lesson_5/tests/nondeterministic/callcc-env2.lambda.out
+++ b/1_k/3_lambda++/lesson_5/tests/nondeterministic/callcc-env2.lambda.out
@@ -1,5 +1,5 @@
 {
   V:K
 #Equals
-  3 ~> .
+  3 ~> .K
 }
diff --git a/1_k/3_lambda++/lesson_5/tests/nondeterministic/callcc-with-let.lambda.out b/1_k/3_lambda++/lesson_5/tests/nondeterministic/callcc-with-let.lambda.out
index 579a5e29..147dbafd 100644
--- a/1_k/3_lambda++/lesson_5/tests/nondeterministic/callcc-with-let.lambda.out
+++ b/1_k/3_lambda++/lesson_5/tests/nondeterministic/callcc-with-let.lambda.out
@@ -1,5 +1,5 @@
 {
   V:K
 #Equals
-  32 ~> .
+  32 ~> .K
 }
diff --git a/1_k/3_lambda++/lesson_5/tests/nondeterministic/closed-variable-capture.lambda.out b/1_k/3_lambda++/lesson_5/tests/nondeterministic/closed-variable-capture.lambda.out
index b6bf03fa..370d2457 100644
--- a/1_k/3_lambda++/lesson_5/tests/nondeterministic/closed-variable-capture.lambda.out
+++ b/1_k/3_lambda++/lesson_5/tests/nondeterministic/closed-variable-capture.lambda.out
@@ -1,5 +1,5 @@
 {
   V:K
 #Equals
-  closure ( x |-> 1 , y , x y ) ~> .
+  closure ( x |-> 1 , y , x y ) ~> .K
 }
diff --git a/1_k/3_lambda++/lesson_5/tests/nondeterministic/free-variable-capture.lambda.out b/1_k/3_lambda++/lesson_5/tests/nondeterministic/free-variable-capture.lambda.out
index 1611b54b..90350803 100644
--- a/1_k/3_lambda++/lesson_5/tests/nondeterministic/free-variable-capture.lambda.out
+++ b/1_k/3_lambda++/lesson_5/tests/nondeterministic/free-variable-capture.lambda.out
@@ -1,23 +1,23 @@
   {
     V:K
   #Equals
-    a ~> #freezer___LAMBDA_Exp_Exp_Exp0_ ( ( lambda x . lambda y . x ) y z ~> . ) ~> .
+    a ~> #freezer___LAMBDA_Exp_Exp_Exp0_ ( ( lambda x . lambda y . x ) y z ~> .K ) ~> .K
   }
 #Or
   {
     V:K
   #Equals
-    y ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( closure ( .Map , x , lambda y . x ) ~> . ) ~> #freezer___LAMBDA_Exp_Exp_Exp0_ ( z ~> . ) ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( a ~> . ) ~> .
+    y ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( closure ( .Map , x , lambda y . x ) ~> .K ) ~> #freezer___LAMBDA_Exp_Exp_Exp0_ ( z ~> .K ) ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( a ~> .K ) ~> .K
   }
 #Or
   {
     V:K
   #Equals
-    y ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( lambda x . lambda y . x ~> . ) ~> #freezer___LAMBDA_Exp_Exp_Exp0_ ( z ~> . ) ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( a ~> . ) ~> .
+    y ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( lambda x . lambda y . x ~> .K ) ~> #freezer___LAMBDA_Exp_Exp_Exp0_ ( z ~> .K ) ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( a ~> .K ) ~> .K
   }
 #Or
   {
     V:K
   #Equals
-    z ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( ( lambda x . lambda y . x ) y ~> . ) ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( a ~> . ) ~> .
+    z ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( ( lambda x . lambda y . x ) y ~> .K ) ~> #freezer___LAMBDA_Exp_Exp_Exp1_ ( a ~> .K ) ~> .K
   }
diff --git a/1_k/3_lambda++/lesson_5/tests/nondeterministic/identity.lambda.out b/1_k/3_lambda++/lesson_5/tests/nondeterministic/identity.lambda.out
index 4d5cd5b9..216e622c 100644
--- a/1_k/3_lambda++/lesson_5/tests/nondeterministic/identity.lambda.out
+++ b/1_k/3_lambda++/lesson_5/tests/nondeterministic/identity.lambda.out
@@ -1,5 +1,5 @@
 {
   V:K
 #Equals
-  closure ( .Map , x , x ) ~> .
+  closure ( .Map , x , x ) ~> .K
 }
diff --git a/1_k/3_lambda++/lesson_5/tests/nondeterministic/if.lambda.out b/1_k/3_lambda++/lesson_5/tests/nondeterministic/if.lambda.out
index 484970b7..0c63378c 100644
--- a/1_k/3_lambda++/lesson_5/tests/nondeterministic/if.lambda.out
+++ b/1_k/3_lambda++/lesson_5/tests/nondeterministic/if.lambda.out
@@ -1,5 +1,5 @@
 {
   V:K
 #Equals
-  10 ~> .
+  10 ~> .K
 }
diff --git a/1_k/3_lambda++/lesson_5/tests/nondeterministic/lets.lambda.out b/1_k/3_lambda++/lesson_5/tests/nondeterministic/lets.lambda.out
index a01c03d1..cbb93410 100644
--- a/1_k/3_lambda++/lesson_5/tests/nondeterministic/lets.lambda.out
+++ b/1_k/3_lambda++/lesson_5/tests/nondeterministic/lets.lambda.out
@@ -1,5 +1,5 @@
 {
   V:K
 #Equals
-  true ~> .
+  true ~> .K
 }
diff --git a/1_k/3_lambda++/lesson_6/tests/deterministic/factorial-let-fix.lambda.out b/1_k/3_lambda++/lesson_6/tests/deterministic/factorial-let-fix.lambda.out
index 1c843187..5522f66a 100644
--- a/1_k/3_lambda++/lesson_6/tests/deterministic/factorial-let-fix.lambda.out
+++ b/1_k/3_lambda++/lesson_6/tests/deterministic/factorial-let-fix.lambda.out
@@ -1,5 +1,5 @@
 {
   V:K
 #Equals
-  3628800 ~> .
+  3628800 ~> .K
 }
diff --git a/1_k/3_lambda++/lesson_6/tests/deterministic/factorial-let.lambda.out b/1_k/3_lambda++/lesson_6/tests/deterministic/factorial-let.lambda.out
index 1c843187..5522f66a 100644
--- a/1_k/3_lambda++/lesson_6/tests/deterministic/factorial-let.lambda.out
+++ b/1_k/3_lambda++/lesson_6/tests/deterministic/factorial-let.lambda.out
@@ -1,5 +1,5 @@
 {
   V:K
 #Equals
-  3628800 ~> .
+  3628800 ~> .K
 }
diff --git a/1_k/3_lambda++/lesson_6/tests/deterministic/factorial-letrec.lambda.out b/1_k/3_lambda++/lesson_6/tests/deterministic/factorial-letrec.lambda.out
index 1c843187..5522f66a 100644
--- a/1_k/3_lambda++/lesson_6/tests/deterministic/factorial-letrec.lambda.out
+++ b/1_k/3_lambda++/lesson_6/tests/deterministic/factorial-letrec.lambda.out
@@ -1,5 +1,5 @@
 {
   V:K
 #Equals
-  3628800 ~> .
+  3628800 ~> .K
 }
diff --git a/1_k/3_lambda++/lesson_6/tests/deterministic/fibbo.lambda.out b/1_k/3_lambda++/lesson_6/tests/deterministic/fibbo.lambda.out
index a7028cde..e4b5bd52 100644
--- a/1_k/3_lambda++/lesson_6/tests/deterministic/fibbo.lambda.out
+++ b/1_k/3_lambda++/lesson_6/tests/deterministic/fibbo.lambda.out
@@ -1,5 +1,5 @@
 {
   V:K
 #Equals
-  13 ~> .
+  13 ~> .K
 }
diff --git a/1_k/3_lambda++/lesson_6/tests/nondeterministic/arithmetic.lambda.out b/1_k/3_lambda++/lesson_6/tests/nondeterministic/arithmetic.lambda.out
index a01c03d1..cbb93410 100644
--- a/1_k/3_lambda++/lesson_6/tests/nondeterministic/arithmetic.lambda.out
+++ b/1_k/3_lambda++/lesson_6/tests/nondeterministic/arithmetic.lambda.out
@@ -1,5 +1,5 @@
 {
   V:K
 #Equals
-  true ~> .
+  true ~> .K
 }
diff --git a/1_k/3_lambda++/lesson_6/tests/nondeterministic/callcc-env1.lambda.out b/1_k/3_lambda++/lesson_6/tests/nondeterministic/callcc-env1.lambda.out
index 0d1534ce..32ce768f 100644
--- a/1_k/3_lambda++/lesson_6/tests/nondeterministic/callcc-env1.lambda.out
+++ b/1_k/3_lambda++/lesson_6/tests/nondeterministic/callcc-env1.lambda.out
@@ -1,5 +1,5 @@
 {
   V:K
 #Equals
-  3 ~> .
+  3 ~> .K
 }
diff --git a/1_k/3_lambda++/lesson_6/tests/nondeterministic/callcc-env2.lambda.out b/1_k/3_lambda++/lesson_6/tests/nondeterministic/callcc-env2.lambda.out
index 0d1534ce..32ce768f 100644
--- a/1_k/3_lambda++/lesson_6/tests/nondeterministic/callcc-env2.lambda.out
+++ b/1_k/3_lambda++/lesson_6/tests/nondeterministic/callcc-env2.lambda.out
@@ -1,5 +1,5 @@
 {
   V:K
 #Equals
-  3 ~> .
+  3 ~> .K
 }
diff --git a/1_k/3_lambda++/lesson_6/tests/nondeterministic/callcc-with-let.lambda.out b/1_k/3_lambda++/lesson_6/tests/nondeterministic/callcc-with-let.lambda.out
index 579a5e29..147dbafd 100644
--- a/1_k/3_lambda++/lesson_6/tests/nondeterministic/callcc-with-let.lambda.out
+++ b/1_k/3_lambda++/lesson_6/tests/nondeterministic/callcc-with-let.lambda.out
@@ -1,5 +1,5 @@
 {
   V:K
 #Equals
-  32 ~> .
+  32 ~> .K
 }
diff --git a/1_k/3_lambda++/lesson_6/tests/nondeterministic/closed-variable-capture.lambda.out b/1_k/3_lambda++/lesson_6/tests/nondeterministic/closed-variable-capture.lambda.out
index b6bf03fa..370d2457 100644
--- a/1_k/3_lambda++/lesson_6/tests/nondeterministic/closed-variable-capture.lambda.out
+++ b/1_k/3_lambda++/lesson_6/tests/nondeterministic/closed-variable-capture.lambda.out
@@ -1,5 +1,5 @@
 {
   V:K
 #Equals
-  closure ( x |-> 1 , y , x y ) ~> .
+  closure ( x |-> 1 , y , x y ) ~> .K
 }
diff --git a/1_k/3_lambda++/lesson_6/tests/nondeterministic/free-variable-capture.lambda.out b/1_k/3_lambda++/lesson_6/tests/nondeterministic/free-variable-capture.lambda.out
index d39db2f2..61b7b5f0 100644
--- a/1_k/3_lambda++/lesson_6/tests/nondeterministic/free-variable-capture.lambda.out
+++ b/1_k/3_lambda++/lesson_6/tests/nondeterministic/free-variable-capture.lambda.out
@@ -1,23 +1,23 @@
   {
     V:K
   #Equals
-    a ~> #freezer___LAMBDA-SYNTAX_Exp_Exp_Exp0_ ( ( lambda x . lambda y . x ) y z ~> . ) ~> .
+    a ~> #freezer___LAMBDA-SYNTAX_Exp_Exp_Exp0_ ( ( lambda x . lambda y . x ) y z ~> .K ) ~> .K
   }
 #Or
   {
     V:K
   #Equals
-    y ~> #freezer___LAMBDA-SYNTAX_Exp_Exp_Exp1_ ( closure ( .Map , x , lambda y . x ) ~> . ) ~> #freezer___LAMBDA-SYNTAX_Exp_Exp_Exp0_ ( z ~> . ) ~> #freezer___LAMBDA-SYNTAX_Exp_Exp_Exp1_ ( a ~> . ) ~> .
+    y ~> #freezer___LAMBDA-SYNTAX_Exp_Exp_Exp1_ ( closure ( .Map , x , lambda y . x ) ~> .K ) ~> #freezer___LAMBDA-SYNTAX_Exp_Exp_Exp0_ ( z ~> .K ) ~> #freezer___LAMBDA-SYNTAX_Exp_Exp_Exp1_ ( a ~> .K ) ~> .K
   }
 #Or
   {
     V:K
   #Equals
-    y ~> #freezer___LAMBDA-SYNTAX_Exp_Exp_Exp1_ ( lambda x . lambda y . x ~> . ) ~> #freezer___LAMBDA-SYNTAX_Exp_Exp_Exp0_ ( z ~> . ) ~> #freezer___LAMBDA-SYNTAX_Exp_Exp_Exp1_ ( a ~> . ) ~> .
+    y ~> #freezer___LAMBDA-SYNTAX_Exp_Exp_Exp1_ ( lambda x . lambda y . x ~> .K ) ~> #freezer___LAMBDA-SYNTAX_Exp_Exp_Exp0_ ( z ~> .K ) ~> #freezer___LAMBDA-SYNTAX_Exp_Exp_Exp1_ ( a ~> .K ) ~> .K
   }
 #Or
   {
     V:K
   #Equals
-    z ~> #freezer___LAMBDA-SYNTAX_Exp_Exp_Exp1_ ( ( lambda x . lambda y . x ) y ~> . ) ~> #freezer___LAMBDA-SYNTAX_Exp_Exp_Exp1_ ( a ~> . ) ~> .
+    z ~> #freezer___LAMBDA-SYNTAX_Exp_Exp_Exp1_ ( ( lambda x . lambda y . x ) y ~> .K ) ~> #freezer___LAMBDA-SYNTAX_Exp_Exp_Exp1_ ( a ~> .K ) ~> .K
   }
diff --git a/1_k/3_lambda++/lesson_6/tests/nondeterministic/identity.lambda.out b/1_k/3_lambda++/lesson_6/tests/nondeterministic/identity.lambda.out
index 4d5cd5b9..216e622c 100644
--- a/1_k/3_lambda++/lesson_6/tests/nondeterministic/identity.lambda.out
+++ b/1_k/3_lambda++/lesson_6/tests/nondeterministic/identity.lambda.out
@@ -1,5 +1,5 @@
 {
   V:K
 #Equals
-  closure ( .Map , x , x ) ~> .
+  closure ( .Map , x , x ) ~> .K
 }
diff --git a/1_k/3_lambda++/lesson_6/tests/nondeterministic/if.lambda.out b/1_k/3_lambda++/lesson_6/tests/nondeterministic/if.lambda.out
index 484970b7..0c63378c 100644
--- a/1_k/3_lambda++/lesson_6/tests/nondeterministic/if.lambda.out
+++ b/1_k/3_lambda++/lesson_6/tests/nondeterministic/if.lambda.out
@@ -1,5 +1,5 @@
 {
   V:K
 #Equals
-  10 ~> .
+  10 ~> .K
 }
diff --git a/1_k/3_lambda++/lesson_6/tests/nondeterministic/lets.lambda.out b/1_k/3_lambda++/lesson_6/tests/nondeterministic/lets.lambda.out
index a01c03d1..cbb93410 100644
--- a/1_k/3_lambda++/lesson_6/tests/nondeterministic/lets.lambda.out
+++ b/1_k/3_lambda++/lesson_6/tests/nondeterministic/lets.lambda.out
@@ -1,5 +1,5 @@
 {
   V:K
 #Equals
-  true ~> .
+  true ~> .K
 }
diff --git a/1_k/5_types/lesson_1.9/tests/factorial-letrec.lambda.out b/1_k/5_types/lesson_1.9/tests/factorial-letrec.lambda.out
index 24bfc83c..922e08a9 100644
--- a/1_k/5_types/lesson_1.9/tests/factorial-letrec.lambda.out
+++ b/1_k/5_types/lesson_1.9/tests/factorial-letrec.lambda.out
@@ -1,5 +1,5 @@
 {
   V:K
 #Equals
-  int ~> .
+  int ~> .K
 }
diff --git a/1_k/5_types/lesson_1.9/tests/ll.lambda.out b/1_k/5_types/lesson_1.9/tests/ll.lambda.out
index 24bfc83c..922e08a9 100644
--- a/1_k/5_types/lesson_1.9/tests/ll.lambda.out
+++ b/1_k/5_types/lesson_1.9/tests/ll.lambda.out
@@ -1,5 +1,5 @@
 {
   V:K
 #Equals
-  int ~> .
+  int ~> .K
 }
diff --git a/1_k/5_types/lesson_1/tests/collatz.imp.out b/1_k/5_types/lesson_1/tests/collatz.imp.out
index 8bbccd1b..bdc3b6ca 100644
--- a/1_k/5_types/lesson_1/tests/collatz.imp.out
+++ b/1_k/5_types/lesson_1/tests/collatz.imp.out
@@ -1,6 +1,6 @@
 <T>
   <k>
-    stmt ~> .
+    stmt ~> .K
   </k>
   <tenv>
     m |-> int
diff --git a/1_k/5_types/lesson_1/tests/div.imp.out b/1_k/5_types/lesson_1/tests/div.imp.out
index 34d0fe87..0cdee1ac 100644
--- a/1_k/5_types/lesson_1/tests/div.imp.out
+++ b/1_k/5_types/lesson_1/tests/div.imp.out
@@ -1,6 +1,6 @@
 <T>
   <k>
-    stmt ~> .
+    stmt ~> .K
   </k>
   <tenv>
     x |-> int
diff --git a/1_k/5_types/lesson_1/tests/io.imp.out b/1_k/5_types/lesson_1/tests/io.imp.out
index 34d0fe87..0cdee1ac 100644
--- a/1_k/5_types/lesson_1/tests/io.imp.out
+++ b/1_k/5_types/lesson_1/tests/io.imp.out
@@ -1,6 +1,6 @@
 <T>
   <k>
-    stmt ~> .
+    stmt ~> .K
   </k>
   <tenv>
     x |-> int
diff --git a/1_k/5_types/lesson_1/tests/locals.imp.out b/1_k/5_types/lesson_1/tests/locals.imp.out
index 74ddde61..068f0983 100644
--- a/1_k/5_types/lesson_1/tests/locals.imp.out
+++ b/1_k/5_types/lesson_1/tests/locals.imp.out
@@ -1,6 +1,6 @@
 <T>
   <k>
-    stmt ~> .
+    stmt ~> .K
   </k>
   <tenv>
     x |-> int
diff --git a/1_k/5_types/lesson_1/tests/primes.imp.out b/1_k/5_types/lesson_1/tests/primes.imp.out
index 94ac6210..e6f3b277 100644
--- a/1_k/5_types/lesson_1/tests/primes.imp.out
+++ b/1_k/5_types/lesson_1/tests/primes.imp.out
@@ -1,6 +1,6 @@
 <T>
   <k>
-    stmt ~> .
+    stmt ~> .K
   </k>
   <tenv>
     i |-> int
diff --git a/1_k/5_types/lesson_1/tests/spawn.imp.out b/1_k/5_types/lesson_1/tests/spawn.imp.out
index 96126dcf..d55ee27d 100644
--- a/1_k/5_types/lesson_1/tests/spawn.imp.out
+++ b/1_k/5_types/lesson_1/tests/spawn.imp.out
@@ -1,6 +1,6 @@
 <T>
   <k>
-    stmt ~> .
+    stmt ~> .K
   </k>
   <tenv>
     t1 |-> int
diff --git a/1_k/5_types/lesson_1/tests/sum-io.imp.out b/1_k/5_types/lesson_1/tests/sum-io.imp.out
index 38d56ba4..08648c75 100644
--- a/1_k/5_types/lesson_1/tests/sum-io.imp.out
+++ b/1_k/5_types/lesson_1/tests/sum-io.imp.out
@@ -1,6 +1,6 @@
 <T>
   <k>
-    stmt ~> .
+    stmt ~> .K
   </k>
   <tenv>
     n |-> int
diff --git a/1_k/5_types/lesson_1/tests/sum.imp.out b/1_k/5_types/lesson_1/tests/sum.imp.out
index 12d51ccd..7ec6b4d3 100644
--- a/1_k/5_types/lesson_1/tests/sum.imp.out
+++ b/1_k/5_types/lesson_1/tests/sum.imp.out
@@ -1,6 +1,6 @@
 <T>
   <k>
-    stmt ~> .
+    stmt ~> .K
   </k>
   <tenv>
     n |-> int
diff --git a/1_k/5_types/lesson_2/tests/factorial-letrec.lambda.out b/1_k/5_types/lesson_2/tests/factorial-letrec.lambda.out
index 24bfc83c..922e08a9 100644
--- a/1_k/5_types/lesson_2/tests/factorial-letrec.lambda.out
+++ b/1_k/5_types/lesson_2/tests/factorial-letrec.lambda.out
@@ -1,5 +1,5 @@
 {
   V:K
 #Equals
-  int ~> .
+  int ~> .K
 }
diff --git a/1_k/5_types/lesson_2/tests/ll.lambda.out b/1_k/5_types/lesson_2/tests/ll.lambda.out
index 24bfc83c..922e08a9 100644
--- a/1_k/5_types/lesson_2/tests/ll.lambda.out
+++ b/1_k/5_types/lesson_2/tests/ll.lambda.out
@@ -1,5 +1,5 @@
 {
   V:K
 #Equals
-  int ~> .
+  int ~> .K
 }
diff --git a/1_k/5_types/lesson_3/tests/factorial-letrec.lambda.out b/1_k/5_types/lesson_3/tests/factorial-letrec.lambda.out
index 24bfc83c..922e08a9 100644
--- a/1_k/5_types/lesson_3/tests/factorial-letrec.lambda.out
+++ b/1_k/5_types/lesson_3/tests/factorial-letrec.lambda.out
@@ -1,5 +1,5 @@
 {
   V:K
 #Equals
-  int ~> .
+  int ~> .K
 }
diff --git a/1_k/5_types/lesson_3/tests/ll.lambda.out b/1_k/5_types/lesson_3/tests/ll.lambda.out
index 24bfc83c..922e08a9 100644
--- a/1_k/5_types/lesson_3/tests/ll.lambda.out
+++ b/1_k/5_types/lesson_3/tests/ll.lambda.out
@@ -1,5 +1,5 @@
 {
   V:K
 #Equals
-  int ~> .
+  int ~> .K
 }