diff --git a/src/ast/datatype_decl_plugin2.cpp b/src/ast/datatype_decl_plugin2.cpp
index 4e60abcce..0030af609 100644
--- a/src/ast/datatype_decl_plugin2.cpp
+++ b/src/ast/datatype_decl_plugin2.cpp
@@ -15,14 +15,13 @@ Author:
 
 Revision History:
 
-    // compute sort sizes and insert them.
-    // have a notion of pre-sort or just attach sort size after declaration.
-
 --*/
-#include "ast/datatype_decl_plugin2.h"
 #include "util/warning.h"
+#include "ast/datatype_decl_plugin2.h"
+#include "ast/array_decl_plugin.h"
 #include "ast/ast_smt2_pp.h"
 
+
 namespace datatype {
 
     func_decl_ref accessor::instantiate(sort_ref_vector const& ps) const {
@@ -78,6 +77,32 @@ namespace datatype {
         BLACK
     };
 
+    namespace param_size {
+        size* size::mk_offset(sort_size const& s) { return alloc(offset, s); }
+        size* size::mk_param(sort_ref& p) { return alloc(sparam, p); }
+        size* size::mk_plus(size* a1, size* a2) { return alloc(plus, a1, a2); }
+        size* size::mk_times(size* a1, size* a2) { return alloc(times, a1, a2); }
+        size* size::mk_times(ptr_vector<size>& szs) {
+            if (szs.empty()) return mk_offset(sort_size(1));
+            if (szs.size() == 1) return szs[0];
+            size* r = szs[0];
+            for (unsigned i = 1; i < szs.size(); ++i) {
+                r = mk_times(r, szs[i]);
+            }
+            return r;
+        }
+        size* size::mk_plus(ptr_vector<size>& szs) {
+            if (szs.empty()) return mk_offset(sort_size(0));
+            if (szs.size() == 1) return szs[0];
+            size* r = szs[0];
+            for (unsigned i = 1; i < szs.size(); ++i) {
+                r = mk_plus(r, szs[i]);
+            }
+            return r;
+        }
+        size* size::mk_power(size* a1, size* a2) { return alloc(power, a1, a2); }
+    }
+
     namespace decl {
 
         plugin::~plugin() {
@@ -125,9 +150,16 @@ namespace datatype {
                                 
                 sort* s = m_manager->mk_sort(name.get_symbol(),
                                              sort_info(m_family_id, k, num_parameters, parameters, true));
-                // compute datatype size
-                sort_size ts = u().get_datatype_size(s); 
-                s->set_num_elements(ts);
+                def* d = 0;
+                if (m_defs.find(s->get_name(), d) && d->sort_size()) {
+                    obj_map<sort, sort_size> S;
+                    for (unsigned i = 1; i < num_parameters; ++i) {
+                        sort* r = to_sort(parameters[i].get_ast());
+                        S.insert(d->params()[i], r->get_num_elements()); 
+                    }
+                    sort_size ts = d->sort_size()->fold(S);
+                    s->set_num_elements(ts);
+                }
                 return s;
             }
             catch (invalid_datatype) {
@@ -256,6 +288,7 @@ namespace datatype {
             if (!u().is_well_founded(sorts.size(), sorts.c_ptr())) {
                 m_manager->raise_exception("datatype is not well-founded");
             }
+            u().compute_datatype_size_functions(m_def_block);
         }
 
         void plugin::del(symbol const& s) {
@@ -418,84 +451,111 @@ namespace datatype {
         }
         return false;
     }
+
+    unsigned util::get_datatype_num_parameter_sorts(sort * ty) {
+        SASSERT(ty->get_num_parameters() >= 1);
+        return ty->get_num_parameters() - 1;
+    }
+
+    sort* util::get_datatype_parameter_sort(sort * ty, unsigned idx) {
+        SASSERT(idx < get_datatype_num_parameter_sorts(ty));
+        return to_sort(ty->get_parameter(idx+1).get_ast());
+    }
+
+    param_size::size* util::get_sort_size(sort_ref_vector const& params, sort* s) {
+        if (params.empty()) {
+            return param_size::size::mk_offset(s->get_num_elements());
+        }
+        if (is_datatype(s)) {
+            param_size::size* sz;
+            obj_map<sort, param_size::size*> S;
+            unsigned n = get_datatype_num_parameter_sorts(s);
+            for (unsigned i = 0; i < n; ++i) {
+                sort* ps = get_datatype_parameter_sort(s, i);
+                sz = get_sort_size(params, ps);
+                sz->inc_ref();
+                S.insert(ps, sz); 
+            }
+            def & d = get_def(s->get_name());
+            sz = d.sort_size()->subst(S);
+            for (auto & kv : S) {
+                kv.m_value->dec_ref();
+            }
+            return sz;
+        }
+        array_util autil(m);
+        if (autil.is_array(s)) {
+            unsigned n = get_array_arity(s);
+            ptr_vector<param_size::size> szs;
+            for (unsigned i = 0; i < n; ++i) {
+                szs.push_back(get_sort_size(params, get_array_domain(s, i)));
+            }
+            param_size::size* sz1 = param_size::size::mk_times(szs);
+            param_size::size* sz2 = get_sort_size(params, get_array_range(s));
+            return param_size::size::mk_power(sz2, sz1);
+        }
+        for (sort* p : params) {           
+            if (s == p) return param_size::size::mk_param(sort_ref(s, m));
+        }
+        return param_size::size::mk_offset(s->get_num_elements());        
+    }
     
-    /**
-       \brief Return the size of the inductive datatype.
-       Pre-condition: The given argument constains the parameters of an inductive datatype.
-    */
-    sort_size util::get_datatype_size(sort* s0) {
-        obj_map<sort, status> already_found;
-        obj_map<sort, sort_size> szs;
-        ptr_vector<sort> todo;
-        todo.push_back(s0);
+    void util::compute_datatype_size_functions(svector<symbol> const& names) {
+        map<symbol, status, symbol_hash_proc, symbol_eq_proc> already_found;
+        map<symbol, param_size::size*, symbol_hash_proc, symbol_eq_proc> szs;
+
+        svector<symbol> todo(names);
         status st;
         while (!todo.empty()) {
-            sort* s  = todo.back();
+            symbol s = todo.back();
             if (already_found.find(s, st) && st == BLACK) {
                 todo.pop_back();
                 continue;
             }
             already_found.insert(s, GRAY);
-            bool     is_very_big       = false;
-            bool     can_process       = true;
-            def const& d = get_def(s);
+            bool is_infinite = false;
+            bool can_process = true;
+            def& d = get_def(s);
             for (constructor const& c : d) {
                 for (accessor const& a : c) {
-                    func_decl_ref ac = a.instantiate(s);
-                    sort* r = ac->get_range();
+                    sort* r = a.range();
                     if (is_datatype(r)) {
-                        if (already_found.find(r, st)) {
+                        symbol s2 = r->get_name();
+                        if (already_found.find(s2, st)) {
                             // type is infinite
-                            if (st == GRAY) return sort_size();
+                            if (st == GRAY) {
+                                is_infinite = true;
+                            }
                         }
-                        else {
-                            todo.push_back(r);
+                        else if (names.contains(s2)) {
+                            todo.push_back(s2);
                             can_process = false;
                         }
                     }
-                    else if (r->is_infinite()) {
-                        // type is infinite
-                        return sort_size();
-                    }
-                    else if (r->is_very_big()) {
-                        is_very_big = true;
-                    }
                 }
             }
+            if (!can_process) {
+                continue;
+            }
+            todo.pop_back();
+            already_found.insert(s, BLACK);
+            if (is_infinite) {
+                d.set_sort_size(param_size::size::mk_offset(sort_size::mk_infinite()));
+                continue;
+            }
 
-            if (can_process) {
-                todo.pop_back();
-                already_found.insert(s, BLACK);
-                if (is_very_big) {
-                    szs.insert(s, sort_size::mk_very_big());
-                }
-                else {
-                    // the type is not infinite nor the number of elements is infinite...
-                    // computing the number of elements
-                    rational num;
-                    def const& d = get_def(s);
-                    for (constructor const& c : d) {
-                        rational c_num(1); 
-                        for (accessor const& a : c) {
-                            func_decl_ref ac = a.instantiate(s);
-                            sort* r = ac->get_range();
-                            if (szs.contains(r)) {
-                                c_num *= rational(szs[r].size(), rational::ui64());
-                            }
-                            else {
-                                SASSERT(!r->is_infinite() && !r->is_very_big());
-                                c_num *= rational(r->get_num_elements().size(), rational::ui64());
-                            }
-                        }
-                        num += c_num;
-                    }
-                    szs.insert(s, sort_size(num));
+            ptr_vector<param_size::size> s_add;        
+            for (constructor const& c : d) {
+                ptr_vector<param_size::size> s_mul;
+                for (accessor const& a : c) {
+                    s_mul.push_back(get_sort_size(d.params(), a.range()));
                 }
+                s_add.push_back(param_size::size::mk_times(s_mul));
             }
+            d.set_sort_size(param_size::size::mk_plus(s_add));
         }
-        return szs[s0];
     }
-
+    
 
     /**
        \brief Return true if the inductive datatype is well-founded.
diff --git a/src/ast/datatype_decl_plugin2.h b/src/ast/datatype_decl_plugin2.h
index fad7ff174..a4a76f346 100644
--- a/src/ast/datatype_decl_plugin2.h
+++ b/src/ast/datatype_decl_plugin2.h
@@ -85,11 +85,100 @@ namespace datatype {
         util& u() const;
     };
 
+    namespace param_size {
+        class size {
+            unsigned m_ref;
+        public:
+            size(): m_ref(0) {}
+            virtual ~size() {}
+            void inc_ref() { ++m_ref; }
+            void dec_ref() { --m_ref; if (m_ref == 0) dealloc(this); }
+            static size* mk_offset(sort_size const& s); 
+            static size* mk_param(sort_ref& p); 
+            static size* mk_plus(size* a1, size* a2); 
+            static size* mk_times(size* a1, size* a2); 
+            static size* mk_plus(ptr_vector<size>& szs);
+            static size* mk_times(ptr_vector<size>& szs);
+            static size* mk_power(size* a1, size* a2);
+            
+            virtual size* subst(obj_map<sort, size*>& S) = 0;
+            virtual sort_size fold(obj_map<sort, sort_size> const& S) = 0;
+            
+        };
+        struct offset : public size {
+            sort_size m_offset;
+            offset(sort_size const& s): m_offset(s) {}
+            virtual ~offset() {}
+            virtual size* subst(obj_map<sort,size*>& S) { return this; }
+            virtual sort_size fold(obj_map<sort, sort_size> const& S) { return m_offset; }
+        };
+        struct plus : public size {
+            size* m_arg1, *m_arg2;
+            plus(size* a1, size* a2): m_arg1(a1), m_arg2(a2) { a1->inc_ref(); a2->inc_ref();}
+            virtual ~plus() { m_arg1->dec_ref(); m_arg2->dec_ref(); }
+            virtual size* subst(obj_map<sort,size*>& S) { return mk_plus(m_arg1->subst(S), m_arg2->subst(S)); }
+            virtual sort_size fold(obj_map<sort, sort_size> const& S) { 
+                sort_size s1 = m_arg1->fold(S);
+                sort_size s2 = m_arg2->fold(S);
+                if (s1.is_infinite()) return s1;
+                if (s2.is_infinite()) return s2;
+                if (s1.is_very_big()) return s1;
+                if (s2.is_very_big()) return s2;
+                rational r = rational(s1.size(), rational::ui64()) + rational(s2.size(), rational::ui64());
+                return sort_size(r);
+            }
+        };
+        struct times : public size {
+            size* m_arg1, *m_arg2;
+            times(size* a1, size* a2): m_arg1(a1), m_arg2(a2) { a1->inc_ref(); a2->inc_ref(); }
+            virtual ~times() { m_arg1->dec_ref(); m_arg2->dec_ref(); }
+            virtual size* subst(obj_map<sort,size*>& S) { return mk_times(m_arg1->subst(S), m_arg2->subst(S)); }
+            virtual sort_size fold(obj_map<sort, sort_size> const& S) { 
+                sort_size s1 = m_arg1->fold(S);
+                sort_size s2 = m_arg2->fold(S);
+                if (s1.is_infinite()) return s1;
+                if (s2.is_infinite()) return s2;
+                if (s1.is_very_big()) return s1;
+                if (s2.is_very_big()) return s2;
+                rational r = rational(s1.size(), rational::ui64()) * rational(s2.size(), rational::ui64());
+                return sort_size(r);
+            }
+        };
+        struct power : public size {
+            size* m_arg1, *m_arg2;
+            power(size* a1, size* a2): m_arg1(a1), m_arg2(a2) { a1->inc_ref(); a2->inc_ref(); }
+            virtual ~power() { m_arg1->dec_ref(); m_arg2->dec_ref(); }
+            virtual size* subst(obj_map<sort,size*>& S) { return mk_power(m_arg1->subst(S), m_arg2->subst(S)); }
+            virtual sort_size fold(obj_map<sort, sort_size> const& S) { 
+                sort_size s1 = m_arg1->fold(S);
+                sort_size s2 = m_arg2->fold(S);
+                // s1^s2
+                if (s1.is_infinite()) return s1;
+                if (s2.is_infinite()) return s2;
+                if (s1.is_very_big()) return s1;
+                if (s2.is_very_big()) return s2;
+                if (s1.size() == 1) return s1;
+                if (s2.size() == 1) return s1;
+                if (s1.size() > (2 << 20) || s2.size() > 10) return sort_size::mk_very_big();
+                rational r = ::power(rational(s1.size(), rational::ui64()), static_cast<unsigned>(s2.size()));
+                return sort_size(r);
+            }
+        };
+        struct sparam : public size {
+            sort_ref m_param;
+            sparam(sort_ref& p): m_param(p) {}
+            virtual ~sparam() {}
+            virtual size* subst(obj_map<sort,size*>& S) { return S[m_param]; }
+            virtual sort_size fold(obj_map<sort, sort_size> const& S) { return S[m_param]; }
+        };
+    };
+
     class def {
         ast_manager&        m;
         util&               m_util;
         symbol              m_name;
         unsigned            m_class_id;
+        param_size::size*   m_sort_size;
         sort_ref_vector     m_params;
         mutable sort_ref    m_sort;
         vector<constructor> m_constructors;
@@ -99,9 +188,13 @@ namespace datatype {
             m_util(u),
             m_name(n),
             m_class_id(class_id),            
+            m_sort_size(0),
             m_params(m, num_params, params), 
             m_sort(m)
         {}
+        ~def() {
+            if (m_sort_size) m_sort_size->dec_ref();
+        }
         void add(constructor& c) {
             m_constructors.push_back(c);
             c.attach(this);
@@ -114,6 +207,8 @@ namespace datatype {
         vector<constructor>::const_iterator end() const { return m_constructors.end(); }
         sort_ref_vector const& params() const { return m_params; }
         util& u() const { return m_util; }
+        param_size::size* sort_size() { return m_sort_size; }
+        void set_sort_size(param_size::size* p) { m_sort_size = p; p->inc_ref(); }
     };
 
     namespace decl {
@@ -155,7 +250,8 @@ namespace datatype {
 
             void del(symbol const& d);
 
-            def const& get_def(sort* s) const { def* d = 0; VERIFY(m_defs.find(datatype_name(s), d)); return *d; }
+            def const& get_def(sort* s) const { return *(m_defs[datatype_name(s)]); }
+            def& get_def(symbol const& s) { return *(m_defs[s]); }
 
         private:
             bool is_value_visit(expr * arg, ptr_buffer<app> & todo) const;
@@ -213,8 +309,11 @@ namespace datatype {
 
         bool is_recursive_core(sort * s) const;
         sort_size get_datatype_size(sort* s0);
+        void compute_datatype_size_functions(svector<symbol> const& names);
+        param_size::size* get_sort_size(sort_ref_vector const& params, sort* s);
         bool is_well_founded(unsigned num_types, sort* const* sorts);
         def const& get_def(sort* s) const;
+        def& get_def(symbol const& s) { return m_plugin->get_def(s); }
         void get_subsorts(sort* s, ptr_vector<sort>& sorts) const;        
 
     public:
diff --git a/src/cmd_context/pdecl.cpp b/src/cmd_context/pdecl.cpp
index 983dbbc78..88ab9f8b8 100644
--- a/src/cmd_context/pdecl.cpp
+++ b/src/cmd_context/pdecl.cpp
@@ -39,15 +39,13 @@ public:
         }
         else {
             SASSERT(m_const == 0);
-            obj_map<sort, void *>::iterator it  = m_map.begin();
-            obj_map<sort, void *>::iterator end = m_map.end();
-            for (; it != end; ++it) {
-                m.m().dec_ref((*it).m_key);
+            for (auto kv : m_map) {
+                m.m().dec_ref(kv.m_key);
                 if (m_num_params == 1) {
-                    m.m().dec_ref(static_cast<sort*>((*it).m_value));
+                    m.m().dec_ref(static_cast<sort*>(kv.m_value));
                 }
                 else {
-                    psort_inst_cache * child = static_cast<psort_inst_cache*>((*it).m_value);
+                    psort_inst_cache * child = static_cast<psort_inst_cache*>(kv.m_value);
                     child->finalize(m);
                     child->~psort_inst_cache();
                     m.a().deallocate(sizeof(psort_inst_cache), child);
@@ -485,20 +483,16 @@ void pconstructor_decl::finalize(pdecl_manager & m) {
 }
 
 bool pconstructor_decl::has_missing_refs(symbol & missing) const {
-    ptr_vector<paccessor_decl>::const_iterator it  = m_accessors.begin();
-    ptr_vector<paccessor_decl>::const_iterator end = m_accessors.end();
-    for (; it != end; ++it) {
-        if ((*it)->has_missing_refs(missing))
+    for (paccessor_decl* a : m_accessors) {
+        if (a->has_missing_refs(missing))
             return true;
     }
     return false;
 }
 
 bool pconstructor_decl::fix_missing_refs(dictionary<int> const & symbol2idx, symbol & missing) {
-    ptr_vector<paccessor_decl>::iterator it  = m_accessors.begin();
-    ptr_vector<paccessor_decl>::iterator end = m_accessors.end();
-    for (; it != end; ++it) {
-        if (!(*it)->fix_missing_refs(symbol2idx, missing))
+    for (paccessor_decl* a : m_accessors) {
+        if (!a->fix_missing_refs(symbol2idx, missing))
             return false;
     }
     return true;
@@ -506,20 +500,16 @@ bool pconstructor_decl::fix_missing_refs(dictionary<int> const & symbol2idx, sym
 
 constructor_decl * pconstructor_decl::instantiate_decl(pdecl_manager & m, sort * const * s) {
     ptr_buffer<accessor_decl> as;
-    ptr_vector<paccessor_decl>::iterator it  = m_accessors.begin();
-    ptr_vector<paccessor_decl>::iterator end = m_accessors.end();
-    for (; it != end; ++it) 
-        as.push_back((*it)->instantiate_decl(m, s));
+    for (paccessor_decl* a : m_accessors) 
+        as.push_back(a->instantiate_decl(m, s));
     return mk_constructor_decl(m_name, m_recogniser_name, as.size(), as.c_ptr());
 }
 
 void pconstructor_decl::display(std::ostream & out, pdatatype_decl const * const * dts) const {
     out << "(" << m_name;
-    ptr_vector<paccessor_decl>::const_iterator it  = m_accessors.begin();
-    ptr_vector<paccessor_decl>::const_iterator end = m_accessors.end();
-    for (; it != end; ++it) {
+    for (paccessor_decl* a : m_accessors) {
         out << " ";
-        (*it)->display(out, dts);
+        a->display(out, dts);
     }
     out << ")";
 }
@@ -538,23 +528,17 @@ void pdatatype_decl::finalize(pdecl_manager & m) {
 }
 
 bool pdatatype_decl::has_missing_refs(symbol & missing) const {
-    ptr_vector<pconstructor_decl>::const_iterator it  = m_constructors.begin();
-    ptr_vector<pconstructor_decl>::const_iterator end = m_constructors.end();
-    for (; it != end; ++it) {
-        if ((*it)->has_missing_refs(missing))
+    for (auto c : m_constructors) 
+        if (c->has_missing_refs(missing))
             return true;
-    }
     return false;
 }
 
 bool pdatatype_decl::has_duplicate_accessors(symbol & duplicated) const {
     hashtable<symbol, symbol_hash_proc, symbol_eq_proc> names;
-    ptr_vector<pconstructor_decl>::const_iterator it  = m_constructors.begin();
-    ptr_vector<pconstructor_decl>::const_iterator end = m_constructors.end();
-    for (; it != end; ++it) {
-        ptr_vector<paccessor_decl> const& acc = (*it)->m_accessors;
-        for (unsigned i = 0; i < acc.size(); ++i) {
-            symbol const& name = acc[i]->get_name();
+    for (auto c : m_constructors) {
+        for (auto a : c->m_accessors) {
+            symbol const& name = a->get_name();
             if (names.contains(name)) {
                 duplicated = name;
                 return true;
@@ -567,10 +551,8 @@ bool pdatatype_decl::has_duplicate_accessors(symbol & duplicated) const {
 
 
 bool pdatatype_decl::fix_missing_refs(dictionary<int> const & symbol2idx, symbol & missing) {
-    ptr_vector<pconstructor_decl>::iterator it  = m_constructors.begin();
-    ptr_vector<pconstructor_decl>::iterator end = m_constructors.end();
-    for (; it != end; ++it) {
-        if (!(*it)->fix_missing_refs(symbol2idx, missing))
+    for (auto c : m_constructors) {
+        if (!c->fix_missing_refs(symbol2idx, missing))
             return false;
     }
     return true;
@@ -578,10 +560,8 @@ bool pdatatype_decl::fix_missing_refs(dictionary<int> const & symbol2idx, symbol
 
 datatype_decl * pdatatype_decl::instantiate_decl(pdecl_manager & m, sort * const * s) {
     ptr_buffer<constructor_decl> cs;
-    ptr_vector<pconstructor_decl>::iterator it  = m_constructors.begin();
-    ptr_vector<pconstructor_decl>::iterator end = m_constructors.end();
-    for (; it != end; ++it) {
-        cs.push_back((*it)->instantiate_decl(m, s));
+    for (auto c : m_constructors) {
+        cs.push_back(c->instantiate_decl(m, s));
     }
     return mk_datatype_decl(m_name, cs.size(), cs.c_ptr());
 }
@@ -624,17 +604,16 @@ sort * pdatatype_decl::instantiate(pdecl_manager & m, unsigned n, sort * const *
 void pdatatype_decl::display(std::ostream & out) const {
     out << "(declare-datatype " << m_name;
     display_sort_args(out, m_num_params);
-    ptr_vector<pconstructor_decl>::const_iterator it  = m_constructors.begin();
-    ptr_vector<pconstructor_decl>::const_iterator end = m_constructors.end();
-    for (bool first = true; it != end; ++it) {
+    bool first = true;
+    for (auto c : m_constructors) {
         if (!first)
             out << " ";
         if (m_parent) {
-            (*it)->display(out, m_parent->children());
+            c->display(out, m_parent->children());
         }
         else {
             pdatatype_decl const * dts[1] = { this };
-            (*it)->display(out, dts);
+            c->display(out, dts);
         }
         first = false;
     }
@@ -647,11 +626,9 @@ pdatatypes_decl::pdatatypes_decl(unsigned id, unsigned num_params, pdecl_manager
     m_datatypes(num_datatypes, dts) {
     m.inc_ref(num_datatypes, dts);
 
-    ptr_vector<pdatatype_decl>::iterator it  = m_datatypes.begin();
-    ptr_vector<pdatatype_decl>::iterator end = m_datatypes.end();
-    for (; it != end; ++it) {
-        SASSERT((*it)->m_parent == 0);
-        (*it)->m_parent = this;
+    for (auto d : m_datatypes) {
+        SASSERT(d->m_parent == 0);
+        d->m_parent = this;
     }
 }
 
@@ -662,36 +639,30 @@ void pdatatypes_decl::finalize(pdecl_manager & m) {
 bool pdatatypes_decl::fix_missing_refs(symbol & missing) {
     TRACE("fix_missing_refs", tout << "pdatatypes_decl::fix_missing_refs\n";);
     dictionary<int> symbol2idx;
-    ptr_vector<pdatatype_decl>::iterator it  = m_datatypes.begin();
-    ptr_vector<pdatatype_decl>::iterator end = m_datatypes.end();
-    for (unsigned idx = 0; it != end; ++it, ++idx)
-        symbol2idx.insert((*it)->get_name(), idx);
-
-    it  = m_datatypes.begin();
-    for (unsigned idx = 0; it != end; ++it, ++idx) {
-        if (!(*it)->fix_missing_refs(symbol2idx, missing))
+    int idx = 0;
+    for (pdatatype_decl* d : m_datatypes) 
+        symbol2idx.insert(d->get_name(), idx++);
+    for (pdatatype_decl* d : m_datatypes) 
+        if (!d->fix_missing_refs(symbol2idx, missing))
             return false;
-    }
     return true;
 }
 
 bool pdatatypes_decl::instantiate(pdecl_manager & m, sort * const * s) {
     datatype_decl_buffer dts;
-    ptr_vector<pdatatype_decl>::iterator it  = m_datatypes.begin();
-    ptr_vector<pdatatype_decl>::iterator end = m_datatypes.end();
-    for (; it != end; ++it) {
-        dts.m_buffer.push_back((*it)->instantiate_decl(m, s));
+    for (auto d : m_datatypes) {
+        dts.m_buffer.push_back(d->instantiate_decl(m, s));
     }
     sort_ref_vector sorts(m.m());
     bool is_ok = m.get_dt_plugin()->mk_datatypes(dts.m_buffer.size(), dts.m_buffer.c_ptr(), m_num_params, s, sorts);
     if (!is_ok)
         return false;
-    it  = m_datatypes.begin();
-    for (unsigned i = 0; it != end; ++it, ++i) {
-        sort * new_dt = sorts.get(i);
-        (*it)->cache(m, s, new_dt);
-        m.save_info(new_dt, *it, m_num_params, s);
-        m.notify_new_dt(new_dt, *it);
+    unsigned i = 0;
+    for (auto d : m_datatypes) {
+        sort * new_dt = sorts.get(i++);
+        d->cache(m, s, new_dt);
+        m.save_info(new_dt, d, m_num_params, s);
+        m.notify_new_dt(new_dt, d);
     }
     return true;
 }
@@ -965,11 +936,9 @@ void pdecl_manager::save_info(sort * s, psort_decl * d, unsigned num_indices, un
 }
 
 void pdecl_manager::reset_sort_info() {
-    obj_map<sort, sort_info *>::iterator it  = m_sort2info.begin();
-    obj_map<sort, sort_info *>::iterator end = m_sort2info.end();
-    for (; it != end; ++it) {
-        sort * s         = (*it).m_key;
-        sort_info * info = (*it).m_value;
+    for (auto kv : m_sort2info) {
+        sort * s         = kv.m_key;
+        sort_info * info = kv.m_value;
         m().dec_ref(s);
         unsigned sz = info->obj_size();
         info->finalize(*this);
diff --git a/src/cmd_context/pdecl.h b/src/cmd_context/pdecl.h
index 2dfbb93ae..1d7203197 100644
--- a/src/cmd_context/pdecl.h
+++ b/src/cmd_context/pdecl.h
@@ -134,20 +134,6 @@ public:
     virtual void display(std::ostream & out) const;
 };
 
-#if 0
-class psort_dt_decl : public psort_decl {
-protected:
-    friend class pdecl_manager;
-    psort_dt_decl(unsigned id, unsigned num_params, pdecl_manager & m, symbol const & n);
-    virtual size_t obj_size() const { return sizeof(psort_dt_decl); }
-    virtual void finalize(pdecl_manager & m);
-    virtual ~psort_dt_decl() {}
-public:
-    virtual sort * instantiate(pdecl_manager & m, unsigned n, sort * const * s);
-    virtual void display(std::ostream & out) const;
-};
-#endif
-
 class datatype_decl_plugin;
 class datatype_decl;
 class constructor_decl;