Fix some spelling errors (mostly in comments).

src/ast/ast_util.h

@@ -123,7 +123,7 @@ inline expr_ref mk_or(expr_ref_vector const& args) { return expr_ref(mk_or(args.
 
 /**
    Return a          if arg = (not a)
-   Retur (not arg)   otherwise
+   Return (not arg)  otherwise
  */
 expr * mk_not(ast_manager & m, expr * arg);
 

src/ast/fpa/fpa2bv_rewriter.cpp

@@ -31,7 +31,7 @@ fpa2bv_rewriter_cfg::fpa2bv_rewriter_cfg(ast_manager & m, fpa2bv_converter & c,
     m_bindings(m)
 {
     updt_params(p);
-    // We need to make sure that the mananger has the BV plugin loaded.
+    // We need to make sure that the manager has the BV plugin loaded.
     symbol s_bv("bv");
     if (!m_manager.has_plugin(s_bv))
         m_manager.register_plugin(s_bv, alloc(bv_decl_plugin));

src/ast/func_decl_dependencies.h

@@ -58,7 +58,7 @@ public:
     void reset();
 
     /**
-       \brief Create a dependecy set.
+       \brief Create a dependency set.
        This set should be populated using #collect_func_decls.
        After populating the set, it must be used as an argument for the #insert method.
 

src/ast/macros/quasi_macros.cpp

@@ -263,7 +263,7 @@ bool quasi_macros::find_macros(unsigned n, expr * const * exprs) {
     m_occurrences.reset();
 
 
-    // Find out how many non-ground appearences for each uninterpreted function there are
+    // Find out how many non-ground appearances for each uninterpreted function there are
     for (unsigned i = 0 ; i < n ; i++)
         find_occurrences(exprs[i]);
 
@@ -301,7 +301,7 @@ bool quasi_macros::find_macros(unsigned n, justified_expr const * exprs) {
     m_occurrences.reset();
     
 
-    // Find out how many non-ground appearences for each uninterpreted function there are    
+    // Find out how many non-ground appearances for each uninterpreted function there are
     for ( unsigned i = 0 ; i < n ; i++ )
         find_occurrences(exprs[i].get_fml());
 

src/ast/pattern/pattern_inference.cpp

@@ -687,7 +687,7 @@ bool pattern_inference_cfg::reduce_quantifier(
             mk_patterns(result2->get_num_decls(), result2->get_expr(), 0, nullptr, new_patterns);
             if (!new_patterns.empty()) {
                 if (m_params.m_pi_warnings) {
-                    warning_msg("pulled nested quantifier to be able to find an useable pattern (quantifier id: %s)", q->get_qid().str().c_str());
+                    warning_msg("pulled nested quantifier to be able to find an usable pattern (quantifier id: %s)", q->get_qid().str().c_str());
                 }
                 new_q = m.update_quantifier(result2, new_patterns.size(), (expr**) new_patterns.c_ptr(), result2->get_expr());
                 if (m.proofs_enabled()) {

src/ast/rewriter/bv_rewriter.cpp

@@ -2679,7 +2679,7 @@ br_status bv_rewriter::mk_ite_core(expr * c, expr * t, expr * e, expr_ref & resu
             }
 
             const unsigned sz = m_util.get_bv_size(rhs);
-            if (sz == 1) { // detect (lhs = N) ? C : D, where N, C, D are 1 bit numberals
+            if (sz == 1) { // detect (lhs = N) ? C : D, where N, C, D are 1 bit numerals
                 numeral rhs_n, e_n, t_n;
                 unsigned rhs_sz, e_sz, t_sz;
                 if (is_numeral(rhs, rhs_n, rhs_sz)

src/ast/rewriter/datatype_rewriter.cpp

@@ -124,7 +124,7 @@ br_status datatype_rewriter::mk_eq_core(expr * lhs, expr * rhs, expr_ref & resul
     //   (= (+ c5 a5) b5)                    <<< NOT SIMPLIFIED WITH RESPECT TO ARITHMETIC
     //   (= (cons a6 nil) (cons b6 nil)))    <<< NOT SIMPLIFIED WITH RESPECT TO DATATYPE theory
     //
-    // Note that asserted_formulas::reduce() applied the simplier many times.
+    // Note that asserted_formulas::reduce() applied the simplifier many times.
     // After the first simplification step we had:
     //  (= a1 b1)
     //  (= (cons a2 (cons a3 (cons (+ a4 1) (cons (+ a5 c5) (cons a6 nil))))))

src/ast/rewriter/der.h

@@ -108,7 +108,7 @@ Revision History:
        apply var_subst using m_map to this child, and store the result in a new children array
   Create a new OR (new body of the quantifier) using the new children
   Then, we create a new quantifier using this new body, and use the function elim_unused_vars to 
-  eliminate the ununsed variables.
+  eliminate the unused variables.
 
   Remark: let us implement the new version inside the class der.
   Use #if 0 ... #endif to comment the old version.

src/ast/rewriter/push_app_ite.h

@@ -41,7 +41,7 @@ struct push_app_ite_cfg : public default_rewriter_cfg {
    \brief Variation of push_app_ite that applies the transformation on nonground terms only.
 
    \remark This functor uses the app::is_ground method. This method is not
-   completly precise, for instance, any term containing a quantifier is marked as non ground.
+   completely precise, for instance, any term containing a quantifier is marked as non ground.
 */
 class ng_push_app_ite_cfg : public push_app_ite_cfg {
 protected: