add lab1 and lab2 exercises

lab2/exercise_1.smv

@@ -0,0 +1,35 @@
+-- Non-deterministic
+
+MODULE main
+    VAR
+        state: 1..4;
+    ASSIGN
+        init(state) := 3;
+        next(state) := case
+            state = 1 : 2;
+            state = 2 : 2;
+            state = 3 : {1, 2, 4};
+            state = 4 : 3;
+        esac;
+
+    DEFINE
+        a := case
+            state = 1 | state = 2 : FALSE;
+            TRUE : TRUE;
+        esac;
+        
+        b := case
+            state = 1 | state = 3 : FALSE;
+            TRUE : TRUE;
+        esac;
+    
+    LTLSPEC F b; -- true
+    LTLSPEC G a; -- false
+    LTLSPEC a U b; -- false
+    LTLSPEC a U X b; -- true
+    LTLSPEC G F b; -- true
+    LTLSPEC F G b; -- false
+
+    LTLSPEC !(G a); -- false
+    LTLSPEC !(a U b); -- false
+    LTLSPEC !(F G b); -- false