Fix some typos. (#7115)

src/smt/smt_internalizer.cpp

@@ -1830,7 +1830,7 @@ namespace smt {
             // Case) there is a variable old_v in the var-list of n.
             //
             // Remark: This variable was moved to the var-list of n due to a add_eq.
-            SASSERT(th->get_enode(old_v) != n); // this varialbe is not owned by n
+            SASSERT(th->get_enode(old_v) != n); // this variable is not owned by n
             SASSERT(n->get_root()->get_th_var(th_id) != null_theory_var); // the root has also a variable in its var-list.
             n->replace_th_var(v, th_id);
             push_trail(replace_th_var_trail( n, th_id, old_v));

src/smt/theory_arith_int.h

@@ -503,7 +503,7 @@ namespace smt {
         theory_var x_i = r.get_base_var();
         
         SASSERT(is_int(x_i));
-        // The following assertion is wrong. It may be violated in mixed-real-interger problems.
+        // The following assertion is wrong. It may be violated in mixed-real-integer problems.
         // The check is_gomory_cut_target will discard rows where any variable contains infinitesimals.
         // SASSERT(m_value[x_i].is_rational()); // infinitesimals are not used for integer variables
         SASSERT(!m_value[x_i].is_int());     // the base variable is not assigned to an integer value.

src/smt/theory_utvpi.cpp

@@ -11,7 +11,7 @@ Author:
 
 Revision History:
 
-    The implementaton is derived from theory_diff_logic.
+    The implementation is derived from theory_diff_logic.
 
 --*/
 #include "smt/theory_utvpi.h"