diff --git a/src/sat/smt/polysat_interval.h b/src/sat/smt/polysat_interval.h
deleted file mode 100644
index 9965dbab1..000000000
--- a/src/sat/smt/polysat_interval.h
+++ /dev/null
@@ -1,224 +0,0 @@
-/*++
-Copyright (c) 2021 Microsoft Corporation
-
-Module Name:
-
-    polysat intervals
-
-Author:
-
-    Nikolaj Bjorner (nbjorner) 2021-03-19
-    Jakob Rath 2021-04-6
-
---*/
-#pragma once
-#include "sat/smt/polysat_types.h"
-#include <optional>
-
-namespace polysat {
-
-    struct pdd_bounds {
-        pdd lo;  ///< lower bound, inclusive
-        pdd hi;  ///< upper bound, exclusive
-    };
-
-    /**
-     * An interval is either [lo; hi[ (excl. upper bound) or the full domain Z_{2^w}.
-     * If lo > hi, the interval wraps around, i.e., represents the union of [lo; 2^w[ and [0; hi[.
-     * Membership test t \in [lo; hi[ is equivalent to t - lo < hi - lo.
-     */
-    class interval {
-        std::optional<pdd_bounds> m_bounds = std::nullopt;
-
-        interval() = default;
-        interval(pdd const& lo, pdd const& hi): m_bounds({lo, hi}) {}
-    public:
-        static interval empty(dd::pdd_manager& m) { return proper(m.zero(), m.zero()); }
-        static interval full() { return {}; }
-        static interval proper(pdd const& lo, pdd const& hi) { return {lo, hi}; }
-
-        interval(interval const&) = default;
-        interval(interval&&) = default;
-        interval& operator=(interval const& other) {
-            m_bounds = std::nullopt;  // clear pdds first to allow changing pdd_manager (probably should change the PDD assignment operator; but for now I want to be able to detect manager confusions)
-            m_bounds = other.m_bounds;
-            return *this;
-        }
-        interval& operator=(interval&& other) {
-            m_bounds = std::nullopt;  // clear pdds first to allow changing pdd_manager
-            m_bounds = std::move(other.m_bounds);
-            return *this;
-        }
-        ~interval() = default;
-
-        bool is_full() const { return !m_bounds; }
-        bool is_proper() const { return !!m_bounds; }
-        bool is_always_empty() const { return is_proper() && lo() == hi(); }
-        pdd const& lo() const { SASSERT(is_proper()); return m_bounds->lo; }
-        pdd const& hi() const { SASSERT(is_proper()); return m_bounds->hi; }
-    };
-
-    inline std::ostream& operator<<(std::ostream& os, interval const& i) {
-        if (i.is_full())
-            return os << "full";
-        else
-            return os << "[" << i.lo() << " ; " << i.hi() << "[";
-    }
-
-    // distance from a to b, wrapping around at mod_value.
-    // basically mod(b - a, mod_value), but distance(0, mod_value, mod_value) = mod_value.
-    inline rational distance(rational const& a, rational const& b, rational const& mod_value) {
-        SASSERT(mod_value.is_power_of_two());
-        SASSERT(0 <= a && a < mod_value);
-        SASSERT(0 <= b && b <= mod_value);
-        rational x = b - a;
-        if (x.is_neg())
-            x += mod_value;
-        return x;
-    }
-
-    class r_interval {
-        rational m_lo;
-        rational m_hi;
-
-        r_interval(rational lo, rational hi)
-            : m_lo(std::move(lo)), m_hi(std::move(hi))
-        {}
-
-    public:
-
-        static r_interval empty() {
-            return {rational::zero(), rational::zero()};
-        }
-
-        static r_interval full() {
-            return {rational(-1), rational::zero()};
-        }
-
-        static r_interval proper(rational lo, rational hi) {
-            SASSERT(0 <= lo);
-            SASSERT(0 <= hi);
-            return {std::move(lo), std::move(hi)};
-        }
-
-        bool is_full() const { return m_lo.is_neg(); }
-        bool is_proper() const { return !is_full(); }
-        bool is_empty() const { return is_proper() && lo() == hi(); }
-        rational const& lo() const { SASSERT(is_proper()); return m_lo; }
-        rational const& hi() const { SASSERT(is_proper()); return m_hi; }
-
-        // this one also supports representing full intervals as [lo;mod_value[
-        static rational len(rational const& lo, rational const& hi, rational const& mod_value) {
-            SASSERT(mod_value.is_power_of_two());
-            SASSERT(0 <= lo && lo < mod_value);
-            SASSERT(0 <= hi && hi <= mod_value);
-            SASSERT(hi != mod_value || lo == 0);  // hi == mod_value only allowed when lo == 0
-            rational len = hi - lo;
-            if (len.is_neg())
-                len += mod_value;
-            return len;
-        }
-
-        rational len(rational const& mod_value) const {
-            SASSERT(is_proper());
-            return len(lo(), hi(), mod_value);
-        }
-
-        // deals only with proper intervals
-        // but works with full intervals represented as [0;mod_value[  -- maybe we should just change representation of full intervals to this always
-        static bool contains(rational const& lo, rational const& hi, rational const& val) {
-            if (lo <= hi)
-                return lo <= val && val < hi;
-            else
-                return val < hi || val >= lo;
-        }
-
-        bool contains(rational const& val) const {
-            if (is_full())
-                return true;
-            else
-                return contains(lo(), hi(), val);
-        }
-
-    };
-
-    class eval_interval {
-        interval m_symbolic;
-        rational m_concrete_lo;
-        rational m_concrete_hi;
-
-        eval_interval(interval&& i, rational const& lo_val, rational const& hi_val):
-            m_symbolic(std::move(i)), m_concrete_lo(lo_val), m_concrete_hi(hi_val) {}
-    public:
-        static eval_interval empty(dd::pdd_manager& m) {
-            return {interval::empty(m), rational::zero(), rational::zero()};
-        }
-
-        static eval_interval full() {
-            return {interval::full(), rational::zero(), rational::zero()};
-        }
-
-        static eval_interval proper(pdd const& lo, rational const& lo_val, pdd const& hi, rational const& hi_val) {
-            SASSERT(0 <= lo_val && lo_val <= lo.manager().max_value());
-            SASSERT(0 <= hi_val && hi_val <= hi.manager().max_value());
-            return {interval::proper(lo, hi), lo_val, hi_val};
-        }
-
-        bool is_full() const { return m_symbolic.is_full(); }
-        bool is_proper() const { return m_symbolic.is_proper(); }
-        bool is_always_empty() const { return m_symbolic.is_always_empty(); }
-        bool is_currently_empty() const { return is_proper() && lo_val() == hi_val(); }
-        interval const& symbolic() const { return m_symbolic; }
-        pdd const& lo() const { return m_symbolic.lo(); }
-        pdd const& hi() const { return m_symbolic.hi(); }
-        rational const& lo_val() const { SASSERT(is_proper()); return m_concrete_lo; }
-        rational const& hi_val() const { SASSERT(is_proper()); return m_concrete_hi; }
-
-        rational current_len() const {
-            SASSERT(is_proper());
-            return mod(hi_val() - lo_val(), lo().manager().two_to_N());
-        }
-
-        bool currently_contains(rational const& val) const {
-            if (is_full())
-                return true;
-            else if (lo_val() <= hi_val())
-                return lo_val() <= val && val < hi_val();
-            else
-                return val < hi_val() || val >= lo_val();
-        }
-
-        bool currently_contains(eval_interval const& other) const {
-            if (is_full())
-                return true;
-            if (other.is_full())
-                return false;
-            // lo <= lo' <= hi' <= hi'
-            if (lo_val() <= other.lo_val() && other.lo_val() <= other.hi_val() && other.hi_val() <= hi_val())
-                return true;
-            if (lo_val() <= hi_val())
-                return false;
-            // hi < lo <= lo' <= hi'
-            if (lo_val() <= other.lo_val() && other.lo_val() <= other.hi_val())
-                return true;
-            // lo' <= hi' <= hi < lo
-            if (other.lo_val() <= other.hi_val() && other.hi_val() <= hi_val())
-                return true;
-            // hi' <= hi < lo <= lo'
-            if (other.hi_val() <= hi_val() && lo_val() <= other.lo_val())
-                return true;
-            return false;
-        }
-
-    };  // class eval_interval
-
-    inline std::ostream& operator<<(std::ostream& os, eval_interval const& i) {
-        if (i.is_full())
-            return os << "full";
-        else {
-            auto& m = i.hi().manager();
-            return os << i.symbolic() << " := [" << m.normalize(i.lo_val()) << ";" << m.normalize(i.hi_val()) << "[";
-        }
-    }
-
-}
diff --git a/src/sat/smt/polysat_substitution.h b/src/sat/smt/polysat_substitution.h
deleted file mode 100644
index a30c6b710..000000000
--- a/src/sat/smt/polysat_substitution.h
+++ /dev/null
@@ -1,212 +0,0 @@
-/*++
-Copyright (c) 2021 Microsoft Corporation
-
-Module Name:
-
-    polysat substitution
-
-Author:
-
-    Nikolaj Bjorner (nbjorner) 2021-03-19
-    Jakob Rath 2021-04-06
-
---*/
-#pragma once
-#include "sat/smt/polysat_types.h"
-
-namespace polysat {
-
-    using assignment_item_t = std::pair<pvar, rational>;
-
-    class substitution_iterator {
-        pdd m_current;
-        substitution_iterator(pdd current) : m_current(std::move(current)) {}
-        friend class substitution;
-
-    public:
-        using value_type = assignment_item_t;
-        using difference_type = std::ptrdiff_t;
-        using pointer = value_type const*;
-        using reference = value_type const&;
-        using iterator_category = std::input_iterator_tag;
-
-        substitution_iterator& operator++() {
-            SASSERT(!m_current.is_val());
-            m_current = m_current.hi();
-            return *this;
-        }
-
-        value_type operator*() const {
-            SASSERT(!m_current.is_val());
-            return { m_current.var(), m_current.lo().val() };
-        }
-
-        bool operator==(substitution_iterator const& other) const { return m_current == other.m_current; }
-        bool operator!=(substitution_iterator const& other) const { return !operator==(other); }
-    };
-
-    /** Substitution for a single bit width. */
-    class substitution {
-        pdd m_subst;
-
-        substitution(pdd p);
-
-    public:
-        substitution(dd::pdd_manager& m);
-        [[nodiscard]] substitution add(pvar var, rational const& value) const;
-        [[nodiscard]] pdd apply_to(pdd const& p) const;
-
-        [[nodiscard]] bool contains(pvar var) const;
-        [[nodiscard]] bool value(pvar var, rational& out_value) const;
-
-        [[nodiscard]] bool empty() const { return m_subst.is_one(); }
-
-        pdd const& to_pdd() const { return m_subst; }
-        unsigned bit_width() const { return to_pdd().power_of_2(); }
-
-        bool operator==(substitution const& other) const { return &m_subst.manager() == &other.m_subst.manager() && m_subst == other.m_subst; }
-        bool operator!=(substitution const& other) const { return !operator==(other); }
-
-        std::ostream& display(std::ostream& out) const;
-
-        using const_iterator = substitution_iterator;
-        const_iterator begin() const { return {m_subst}; }
-        const_iterator end() const { return {m_subst.manager().one()}; }
-    };
-
-    /** Full variable assignment, may include variables of varying bit widths. */
-    class assignment {
-        vector<assignment_item_t>               m_pairs;
-        mutable scoped_ptr_vector<substitution> m_subst;
-        vector<substitution>                    m_subst_trail;
-
-        substitution& subst(unsigned sz);
-        solver& s() const { return *m_solver; }
-    public:
-        assignment(solver& s);
-        // prevent implicit copy, use clone() if you do need a copy
-        assignment(assignment const&) = delete;
-        assignment& operator=(assignment const&) = delete;
-        assignment(assignment&&) = default;
-        assignment& operator=(assignment&&) = default;
-        assignment clone() const;
-
-        void push(pvar var, rational const& value);
-        void pop();
-
-        pdd apply_to(pdd const& p) const;
-
-        bool contains(pvar var) const;
-        bool value(pvar var, rational& out_value) const;
-        rational value(pvar var) const { rational val; VERIFY(value(var, val)); return val; }
-        bool empty() const { return pairs().empty(); }
-        substitution const& subst(unsigned sz) const;
-        vector<assignment_item_t> const& pairs() const { return m_pairs; }
-        using const_iterator = decltype(m_pairs)::const_iterator;
-        const_iterator begin() const { return pairs().begin(); }
-        const_iterator end() const { return pairs().end(); }
-
-        std::ostream& display(std::ostream& out) const;
-    };
-
-    inline std::ostream& operator<<(std::ostream& out, substitution const& sub) { return sub.display(out); }
-
-    inline std::ostream& operator<<(std::ostream& out, assignment const& a) { return a.display(out); }
-}
-
-namespace polysat {
-
-    enum class search_item_k
-    {
-        assignment,
-        boolean,
-    };
-
-    class search_item {
-        search_item_k m_kind;
-        union {
-            pvar m_var;
-            sat::literal m_lit;
-        };
-        bool m_resolved = false; // when marked as resolved it is no longer valid to reduce the conflict state
-
-        search_item(pvar var): m_kind(search_item_k::assignment), m_var(var) {}
-        search_item(sat::literal lit): m_kind(search_item_k::boolean), m_lit(lit) {}
-    public:
-        static search_item assignment(pvar var) { return search_item(var); }
-        static search_item boolean(sat::literal lit) { return search_item(lit); }
-        bool is_assignment() const { return m_kind == search_item_k::assignment; }
-        bool is_boolean() const { return m_kind == search_item_k::boolean; }
-        bool is_resolved() const { return m_resolved; }
-        search_item_k kind() const { return m_kind; }
-        pvar var() const { SASSERT(is_assignment()); return m_var; }
-        sat::literal lit() const { SASSERT(is_boolean()); return m_lit; }
-        void set_resolved() { m_resolved = true; }
-    };
-
-    class search_state {
-        solver&             s;
-
-        vector<search_item> m_items;
-        assignment          m_assignment;
-
-        // store index into m_items
-        unsigned_vector     m_pvar_to_idx;
-        unsigned_vector     m_bool_to_idx;
-
-        bool value(pvar v, rational& r) const;
-
-    public:
-        search_state(solver& s): s(s), m_assignment(s) {}
-        unsigned size() const { return m_items.size(); }
-        search_item const& back() const { return m_items.back(); }
-        search_item const& operator[](unsigned i) const { return m_items[i]; }
-
-        assignment const& get_assignment() const { return m_assignment; }
-        substitution const& subst(unsigned sz) const { return m_assignment.subst(sz); }
-
-        // TODO: implement the following method if we actually need the assignments without resolved items already during conflict resolution
-        //       (no separate trail needed, just a second m_subst and an index into the trail, I think)
-        //       (update on set_resolved? might be one iteration too early, looking at the old solver::resolve_conflict loop)
-        substitution const& unresolved_assignment(unsigned sz) const;
-
-        void push_assignment(pvar v, rational const& r);
-        void push_boolean(sat::literal lit);
-        void pop();
-
-        unsigned get_pvar_index(pvar v) const;
-        unsigned get_bool_index(sat::bool_var var) const;
-        unsigned get_bool_index(sat::literal lit) const { return get_bool_index(lit.var()); }
-
-        void set_resolved(unsigned i) { m_items[i].set_resolved(); }
-
-        using const_iterator = decltype(m_items)::const_iterator;
-        const_iterator begin() const { return m_items.begin(); }
-        const_iterator end() const { return m_items.end(); }
-
-        std::ostream& display(std::ostream& out) const;
-        std::ostream& display(search_item const& item, std::ostream& out) const;
-        std::ostream& display_verbose(std::ostream& out) const;
-        std::ostream& display_verbose(search_item const& item, std::ostream& out) const;
-    };
-
-    struct search_state_pp {
-        search_state const& s;
-        bool verbose;
-        search_state_pp(search_state const& s, bool verbose = false) : s(s), verbose(verbose) {}
-    };
-
-    struct search_item_pp {
-        search_state const& s;
-        search_item const& i;
-        bool verbose;
-        search_item_pp(search_state const& s, search_item const& i, bool verbose = false) : s(s), i(i), verbose(verbose) {}
-    };
-
-    inline std::ostream& operator<<(std::ostream& out, search_state const& s) { return s.display(out); }
-
-    inline std::ostream& operator<<(std::ostream& out, search_state_pp const& p) { return p.verbose ? p.s.display_verbose(out) : p.s.display(out); }
-
-    inline std::ostream& operator<<(std::ostream& out, search_item_pp const& p) { return p.verbose ? p.s.display_verbose(p.i, out) : p.s.display(p.i, out); }
-
-}