new test files

tests/sequences/example-7.alt

+node A
+  flow f : bool;
+  state x, y : bool;
+  event a, b;
+  assert f = x
+  trans x |- a -> x:= not x, y := not x;
+        y |- b -> y := x;
+edon
+
+target-reduction A f

tests/sequences/example-8.alt

+node A
+  flow x : bool;
+  state y : [0,5];
+  event e, f
+  trans 
+        x |- e -> ;
+        true |- e -> y := 2;
+        true |- f -> y := y+1 ;
+  assert x = (y > 2);
+         y = 3;
+edon