fixed StringMinChange

src/test/scala/leon/integration/solvers/StringSolverSuite.scala

@@ -252,11 +252,11 @@ T2: ret Pop() -> 5"""
     val v = idMap("v")
     val w = idMap("w")
     val solutions = solveMinChange(problem, Map(u -> "a", v -> "b", w -> "c"))
-    solutions(0) should equal (Map(v -> "kb"))
-    solutions(1) should equal (Map(u -> "ak"))
-    (2 to 5).toSet.map((i: Int) => solutions(i)) should equal (Set(Map(v -> "", w -> "kbc")
-    , Map(v -> "k", w -> "bc")
-    , Map(v -> "kb", w -> "c")
-    , Map(v -> "kbc", w -> "")))
+    solutions(0) should equal (Map(u -> "ak"))
+    solutions(1) should equal (Map(v -> "kb"))
+    (2 to 5).toSet.map((i: Int) => solutions(i)) should equal (Set(Map(u -> "", v -> "akb")
+    , Map(u -> "a", v -> "kb")
+    , Map(u -> "ak", v -> "b")
+    , Map(u -> "akb", v -> "")))
   }
 }
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