diff --git a/exl/borrow.fzs b/exl/borrow.fzs
index 3a538a9..80c3d38 100644
--- a/exl/borrow.fzs
+++ b/exl/borrow.fzs
@@ -7,12 +7,11 @@ fn doSome(A a) A
 {
   // NOTE: section below won't change `a.some` value
 
-  // if (a.some < 1)
-  // {
-  //   a.some = 1;
-  //   return a;
-  // }
-  a.some = 1;
+  if (a.some < 1)
+  {
+    a.some = 1;
+    return a;
+  }
 
   return a;
 }
@@ -27,10 +26,20 @@ fn doSomeNew() A
 
 A a = new A;
 a.some = 0;
-printline(a);
+if (a.some != 0)
+{
+  printline("Test failed (first a.some != 0)");
+  exit(1);
+}
+else printline(a);
 
 a = doSome(a);
-printline(a);
+if (a.some != 1)
+{
+  printline("Test failed (2nd a.some != 1)");
+  exit(1);
+}
+else printline(a);
 
 A b = doSomeNew();
 printline(b);
diff --git a/exl/class.fzs b/exl/class.fzs
index f73a12d..a7ac0f5 100644
--- a/exl/class.fzs
+++ b/exl/class.fzs
@@ -28,5 +28,9 @@ printline(obj.y);
 
 if (obj.x == 10 && obj.y == 10)
   printline("Test passed");
-else printline("Test failed");
+else
+{
+  printline("Test failed");
+  exit(1);
+}
 
diff --git a/exl/conditions.fzs b/exl/conditions.fzs
index b7c5a83..a49e79d 100644
--- a/exl/conditions.fzs
+++ b/exl/conditions.fzs
@@ -1,13 +1,17 @@
 bool flag = true;
 
 if (!flag)
+{
   printline("buhhh, flag is not true");
+  exit(1);
+}
 else if (2 + 2 >= 4)
 {
   printline ("two plus two is four");
 }
 else {
   printline("gotcha");
+  exit(1);
 }
 
 {
diff --git a/exl/fn.fzs b/exl/fn.fzs
index dde5dad..2d6214c 100644
--- a/exl/fn.fzs
+++ b/exl/fn.fzs
@@ -15,10 +15,18 @@ printline("Test #1: fibonacci");
 int result = fib(7);
 if (result == 13)
   printline("Recurse test passed");
-else printline("Recurse test failed");
+else
+{
+  printline("Recurse test failed");
+  exit(1);
+}
 
 printline("Test #2: sum");
 if (sum(2, 2) == 4)
   printline("Sum test passed");
-else printline("Sum test failed");
+else
+{
+  printline("Sum test failed");
+  exit(1);
+}
 
diff --git a/exl/hard-1.fzs b/exl/hard-1.fzs
index 9588901..e6d1ba3 100644
--- a/exl/hard-1.fzs
+++ b/exl/hard-1.fzs
@@ -58,5 +58,9 @@ printline(total);
 
 if (total == 16)
   printline("Tests passed!");
-else printline("Tests failed");
+else
+{
+  printline("Tests failed");
+  exit(1);
+}
 
diff --git a/exl/raii.fzs b/exl/raii.fzs
index 998d06e..f9e2e83 100644
--- a/exl/raii.fzs
+++ b/exl/raii.fzs
@@ -21,14 +21,26 @@ a.name = "Buryatka";
 a.age = 5;
 
 Animal b = a.copy();
-a.name = "Gavryusha";
-a.age = 10;
+b.name = "Gavryusha";
+b.age = 10;
 
 printline(a);
 printline(b);
 
+printline("Types are same:");
+printline(a.type == b.type);
+
+printline("Names are NOT the same");
+printline(a.name != b.name);
+
+printline("1st age less than 2nd");
+printline(a.age < b.age);
+
 if (a.type == b.type && a.name != b.name && a.age < b.age)
   printline("Test passed");
 else
+{
   printline("Test failed");
+  exit(1);
+}