Fix some spelling errors (mostly in comments).

src/tactic/arith/fm_tactic.cpp

@@ -1231,7 +1231,7 @@ class fm_tactic : public tactic {
         }
         
         // An integer variable x may be eliminated, if 
-        //   1- All variables in the contraints it occur are integer.
+        //   1- All variables in the constraints it occur are integer.
         //   2- The coefficient of x in all lower bounds (or all upper bounds) is unit.
         bool can_eliminate(var x) const {
             if (!is_int(x))

src/tactic/bv/bvarray2uf_rewriter.cpp

@@ -40,7 +40,7 @@ bvarray2uf_rewriter_cfg::bvarray2uf_rewriter_cfg(ast_manager & m, params_ref con
     m_fmc(nullptr),
     extra_assertions(m) {
     updt_params(p);
-    // We need to make sure that the mananger has the BV and array plugins loaded.
+    // We need to make sure that the manager has the BV and array plugins loaded.
     symbol s_bv("bv");
     if (!m_manager.has_plugin(s_bv))
         m_manager.register_plugin(s_bv, alloc(bv_decl_plugin));

src/tactic/core/cofactor_elim_term_ite.cpp

@@ -197,7 +197,7 @@ struct cofactor_elim_term_ite::imp {
                     switch (arg->get_kind()) {
                     case AST_VAR:
                     case AST_QUANTIFIER:
-                        // ingore quantifiers
+                        // ignore quantifiers
                         break;
                     case AST_APP:
                         if (to_app(arg)->get_num_args() > 0) {
@@ -264,7 +264,7 @@ struct cofactor_elim_term_ite::imp {
                     switch (arg->get_kind()) {
                     case AST_VAR:
                     case AST_QUANTIFIER:
-                        // ingore quantifiers
+                        // ignore quantifiers
                         break;
                     case AST_APP:
                         if (to_app(arg)->get_num_args() > 0) {

src/tactic/core/pb_preprocess_tactic.cpp

@@ -273,8 +273,8 @@ private:
     }
 
     /**
-       \brief decompose large sums into smaller sums by intoducing
-       auxilary variables.
+       \brief decompose large sums into smaller sums by introducing
+       auxiliary variables.
     */
     void decompose(goal_ref const& g) {
         expr_ref fml1(m), fml2(m);

src/tactic/model_converter.h

@@ -31,7 +31,7 @@ Notes:
 
     This property holds for both eval, that decides on a fixed value
     for constants that have no interpretation in m and for 'peval' 
-    (partial eval) that retuns just the constants that are unfixed.
+    (partial eval) that returns just the constants that are unfixed.
     (in the model evaluator one can control this behavior using a 
     configuration flag)
 
@@ -48,7 +48,7 @@ Notes:
        mc(G) & F_s is SAT  iff G & F is SAT
 
     For a model converter that is a sequence of definitions and removals
-    of functions we can obtain mc(G) by adding back or expanding definitinos
+    of functions we can obtain mc(G) by adding back or expanding definitions
     that are required to interpret G fully in the context of F_s.
 
 --*/

src/tactic/nlsat_smt/nl_purify_tactic.cpp

@@ -8,7 +8,7 @@ Module Name:
 Abstract:
 
     Tactic for purifying quantifier-free formulas that mix QF_NRA and other theories.
-    It is designed to allow cooprating between the nlsat solver and other theories
+    It is designed to allow cooperation between the nlsat solver and other theories
     in a decoupled way.
 
     Let goal be formula F.
@@ -446,7 +446,7 @@ private:
             expr* pred = fresh_preds[i];
             if (mdl->eval(pred, tmp)) {
                 polarity_t pol = m_polarities.find(pred);
-                // if assumptinon literals are used to satisfy NL state,
+                // if assumption literals are used to satisfy NL state,
                 // we have to assume them when satisfying SMT state
                 if (pol != pol_neg && m.is_false(tmp)) {
                     m_asms.push_back(m.mk_not(pred));
@@ -767,7 +767,7 @@ public:
         // then annotate subformulas by polarities,
         // finally extract polynomial inequalities by
         // creating a place-holder predicate inside the
-        // original goal and extracing pure nlsat clauses.
+        // original goal and extracting pure nlsat clauses.
         r.set_interface_var_mode();
         rewrite_goal(r, g); 
         if (!g->unsat_core_enabled()) {

src/tactic/sls/sls_engine.cpp

@@ -182,7 +182,7 @@ bool sls_engine::what_if(
     // Andreas: Had this idea on my last day. Maybe we could add a noise here similar to the one that worked so well for ucb assertion selection.
     // r += 0.0001 * m_tracker.get_random_uint(8);
 
-    // Andreas: For some reason it is important to use > here instead of >=. Probably related to prefering the LSB.
+    // Andreas: For some reason it is important to use > here instead of >=. Probably related to preferring the LSB.
     if (r > best_score) {
         best_score = r;
         best_const = fd_inx;

src/tactic/smtlogics/qfbv_tactic.cpp

@@ -36,7 +36,7 @@ Notes:
 static tactic * mk_qfbv_preamble(ast_manager& m, params_ref const& p) {
 
     params_ref solve_eq_p;
-    // conservative guassian elimination.
+    // conservative gaussian elimination.
     solve_eq_p.set_uint("solve_eqs_max_occs", 2);
 
     params_ref simp2_p = p;