remove unused

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

src/smt/seq_regex.cpp

@@ -544,7 +544,6 @@ namespace smt {
         sort* elem_sort = nullptr, *seq_sort = nullptr;
         VERIFY(u().is_re(r, seq_sort));
         VERIFY(u().is_seq(seq_sort, elem_sort));
-        sort* domain[2] = { m.get_sort(n), a().mk_int() };
         return sk().mk("re.first", n, a().mk_int(r->get_id()), elem_sort);
     }
 }

src/smt/smt_induction.cpp

@@ -94,7 +94,9 @@ collect_induction_literals::collect_induction_literals(context& ctx, ast_manager
     m(m),
     vs(vs),
     m_literal_index(0)
-{}
+{
+    (void)vs;
+}
     
 literal_vector collect_induction_literals::operator()() {    
     literal_vector candidates = pre_select();

src/smt/theory_str.cpp

@@ -8138,7 +8138,7 @@ namespace smt {
     // Returns true if this can be done in a valid way, placing the converted value in the argument.
     // Otherwise, returns false, if str is empty or contains non-digit characters.
     bool theory_str::string_integer_conversion_valid(zstring str, rational& converted) const {
-        bool valid = true;
+        // bool valid = true;
         converted = rational::zero();
         rational ten(10);
         if (str.length() == 0) {