/**
Copyright (c) 2017 Arie Gurfinkel

 Deprecated implementation of model evaluator. To be removed.
*/

#include <sstream>
#include "ast/array_decl_plugin.h"
#include "ast/ast_pp.h"
#include "ast/rewriter/bool_rewriter.h"
#include "muz/base/dl_util.h"
#include "ast/for_each_expr.h"
#include "params/smt_params.h"
#include "model/model.h"
#include "util/ref_vector.h"
#include "ast/rewriter/rewriter.h"
#include "ast/rewriter/rewriter_def.h"
#include "util/util.h"
#include "muz/spacer/spacer_manager.h"
#include "muz/spacer/spacer_legacy_mev.h"
#include "muz/spacer/spacer_util.h"
#include "ast/arith_decl_plugin.h"
#include "ast/rewriter/expr_replacer.h"
#include "model/model_smt2_pp.h"
#include "ast/scoped_proof.h"
#include "qe/lite/qe_lite_tactic.h"
#include "muz/spacer/spacer_qe_project.h"
#include "model/model_pp.h"
#include "ast/rewriter/expr_safe_replace.h"

#include "ast/datatype_decl_plugin.h"
#include "ast/bv_decl_plugin.h"

namespace old {

/////////////////////////
// model_evaluator
//


void model_evaluator::assign_value(expr* e, expr* val)
{
    rational r;
    if (m.is_true(val)) {
        set_true(e);
    } else if (m.is_false(val)) {
        set_false(e);
    } else if (m_arith.is_numeral(val, r)) {
        set_number(e, r);
    } else if (m.is_value(val)) {
        set_value(e, val);
    } else {
        IF_VERBOSE(3, verbose_stream() << "Not evaluated " << mk_pp(e, m) << "\n";);
        TRACE(old_spacer, tout << "Variable is not tracked: " << mk_pp(e, m) << "\n";);
        set_x(e);
    }
}

void model_evaluator::setup_model(const model_ref& model)
{
    m_numbers.reset();
    m_values.reset();
    m_model = model.get();
    rational r;
    unsigned sz = model->get_num_constants();
    for (unsigned i = 0; i < sz; i++) {
        func_decl * d = model->get_constant(i);
        expr* val = model->get_const_interp(d);
        expr* e = m.mk_const(d);
        m_refs.push_back(e);
        assign_value(e, val);
    }
}

void model_evaluator::reset()
{
    m1.reset();
    m2.reset();
    m_values.reset();
    m_visited.reset();
    m_numbers.reset();
    m_refs.reset();
    m_model = nullptr;
}


void model_evaluator::minimize_literals(ptr_vector<expr> const& formulas,
                                        const model_ref& mdl, expr_ref_vector& result)
{

    TRACE(old_spacer,
          tout << "formulas:\n";
          for (unsigned i = 0; i < formulas.size(); ++i) tout << mk_pp(formulas[i], m) << "\n";
         );

    expr_ref tmp(m);
    ptr_vector<expr> tocollect;

    setup_model(mdl);
    collect(formulas, tocollect);
    for (unsigned i = 0; i < tocollect.size(); ++i) {
        expr* e = tocollect[i];
        expr* e1, *e2;
        SASSERT(m.is_bool(e));
        SASSERT(is_true(e) || is_false(e));
        if (is_true(e)) {
            result.push_back(e);
        }
        // hack to break disequalities for arithmetic variables.
        else if (m.is_eq(e, e1, e2) && m_arith.is_int_real(e1)) {
            if (get_number(e1) < get_number(e2)) {
                result.push_back(m_arith.mk_lt(e1, e2));
            } else {
                result.push_back(m_arith.mk_lt(e2, e1));
            }
        } else {
            result.push_back(m.mk_not(e));
        }
    }
    reset();
    TRACE(old_spacer,
          tout << "minimized model:\n";
          for (unsigned i = 0; i < result.size(); ++i) tout << mk_pp(result[i].get(), m) << "\n";
         );
}

void model_evaluator::process_formula(app* e, ptr_vector<expr>& todo, ptr_vector<expr>& tocollect)
{
    SASSERT(m.is_bool(e));
    SASSERT(is_true(e) || is_false(e));
    unsigned v = is_true(e);
    unsigned sz = e->get_num_args();
    expr* const* args = e->get_args();
    if (e->get_family_id() == m.get_basic_family_id()) {
        switch (e->get_decl_kind()) {
        case OP_TRUE:
            break;
        case OP_FALSE:
            break;
        case OP_EQ:
            if (args[0] == args[1]) {
                SASSERT(v);
                // no-op
            } else if (m.is_bool(args[0])) {
                todo.append(sz, args);
            } else {
                tocollect.push_back(e);
            }
            break;
        case OP_DISTINCT:
            tocollect.push_back(e);
            break;
        case OP_ITE:
            if (args[1] == args[2]) {
                tocollect.push_back(args[1]);
            } else if (is_true(args[1]) && is_true(args[2])) {
                todo.append(2, args + 1);
            } else if (is_false(args[1]) && is_false(args[2])) {
                todo.append(2, args + 1);
            } else if (is_true(args[0])) {
                todo.append(2, args);
            } else {
                SASSERT(is_false(args[0]));
                todo.push_back(args[0]);
                todo.push_back(args[2]);
            }
            break;
        case OP_AND:
            if (v) {
                todo.append(sz, args);
            } else {
                unsigned i = 0;
                for (; !is_false(args[i]) && i < sz; ++i);
                if (i == sz) {
                    fatal_error(1);
                }
                VERIFY(i < sz);
                todo.push_back(args[i]);
            }
            break;
        case OP_OR:
            if (v) {
                unsigned i = 0;
                for (; !is_true(args[i]) && i < sz; ++i);
                if (i == sz) {
                    fatal_error(1);
                }
                VERIFY(i < sz);
                todo.push_back(args[i]);
            } else {
                todo.append(sz, args);
            }
            break;
        case OP_XOR:
        case OP_NOT:
            todo.append(sz, args);
            break;
        case OP_IMPLIES:
            if (v) {
                if (is_true(args[1])) {
                    todo.push_back(args[1]);
                } else if (is_false(args[0])) {
                    todo.push_back(args[0]);
                } else {
                    IF_VERBOSE(0, verbose_stream() << "Term not handled " << mk_pp(e, m) << "\n";);
                    UNREACHABLE();
                }
            } else {
                todo.append(sz, args);
            }
            break;
        default:
            IF_VERBOSE(0, verbose_stream() << "Term not handled " << mk_pp(e, m) << "\n";);
            UNREACHABLE();
        }
    } else {
        tocollect.push_back(e);
    }
}

void model_evaluator::collect(ptr_vector<expr> const& formulas, ptr_vector<expr>& tocollect)
{
    ptr_vector<expr> todo;
    todo.append(formulas);
    m_visited.reset();

    VERIFY(check_model(formulas));

    while (!todo.empty()) {
        app*  e = to_app(todo.back());
        todo.pop_back();
        if (!m_visited.is_marked(e)) {
            process_formula(e, todo, tocollect);
            m_visited.mark(e, true);
        }
    }
    m_visited.reset();
}

void model_evaluator::eval_arith(app* e)
{
    rational r, r2;

#define ARG1 e->get_arg(0)
#define ARG2 e->get_arg(1)

    unsigned arity = e->get_num_args();
    for (unsigned i = 0; i < arity; ++i) {
        expr* arg = e->get_arg(i);
        if (is_x(arg)) {
            set_x(e);
            return;
        }
        SASSERT(!is_unknown(arg));
    }
    switch (e->get_decl_kind()) {
    case OP_NUM:
        VERIFY(m_arith.is_numeral(e, r));
        set_number(e, r);
        break;
    case OP_IRRATIONAL_ALGEBRAIC_NUM:
        set_x(e);
        break;
    case OP_LE:
        set_bool(e, get_number(ARG1) <= get_number(ARG2));
        break;
    case OP_GE:
        set_bool(e, get_number(ARG1) >= get_number(ARG2));
        break;
    case OP_LT:
        set_bool(e, get_number(ARG1) < get_number(ARG2));
        break;
    case OP_GT:
        set_bool(e, get_number(ARG1) > get_number(ARG2));
        break;
    case OP_ADD:
        r = rational::zero();
        for (unsigned i = 0; i < arity; ++i) {
            r += get_number(e->get_arg(i));
        }
        set_number(e, r);
        break;
    case OP_SUB:
        r = get_number(e->get_arg(0));
        for (unsigned i = 1; i < arity; ++i) {
            r -= get_number(e->get_arg(i));
        }
        set_number(e, r);
        break;
    case OP_UMINUS:
        SASSERT(arity == 1);
        set_number(e, -get_number(e->get_arg(0)));
        break;
    case OP_MUL:
        r = rational::one();
        for (unsigned i = 0; i < arity; ++i) {
            r *= get_number(e->get_arg(i));
        }
        set_number(e, r);
        break;
    case OP_DIV:
        SASSERT(arity == 2);
        r = get_number(ARG2);
        if (r.is_zero()) {
            set_x(e);
        } else {
            set_number(e, get_number(ARG1) / r);
        }
        break;
    case OP_IDIV:
        SASSERT(arity == 2);
        r = get_number(ARG2);
        if (r.is_zero()) {
            set_x(e);
        } else {
            set_number(e, div(get_number(ARG1), r));
        }
        break;
    case OP_REM:
        // rem(v1,v2) = if v2 >= 0 then mod(v1,v2) else -mod(v1,v2)
        SASSERT(arity == 2);
        r = get_number(ARG2);
        if (r.is_zero()) {
            set_x(e);
        } else {
            r2 = mod(get_number(ARG1), r);
            if (r.is_neg()) { r2.neg(); }
            set_number(e, r2);
        }
        break;
    case OP_MOD:
        SASSERT(arity == 2);
        r = get_number(ARG2);
        if (r.is_zero()) {
            set_x(e);
        } else {
            set_number(e, mod(get_number(ARG1), r));
        }
        break;
    case OP_TO_REAL:
        SASSERT(arity == 1);
        set_number(e, get_number(ARG1));
        break;
    case OP_TO_INT:
        SASSERT(arity == 1);
        set_number(e, floor(get_number(ARG1)));
        break;
    case OP_IS_INT:
        SASSERT(arity == 1);
        set_bool(e, get_number(ARG1).is_int());
        break;
    case OP_POWER:
        set_x(e);
        break;
    default:
        IF_VERBOSE(0, verbose_stream() << "Term not handled " << mk_pp(e, m) << "\n";);
        UNREACHABLE();
        break;
    }
}

void model_evaluator::inherit_value(expr* e, expr* v)
{
    expr* w;
    SASSERT(!is_unknown(v));
    SASSERT(e->get_sort() == v->get_sort());
    if (is_x(v)) {
        set_x(e);
    } else if (m.is_bool(e)) {
        SASSERT(m.is_bool(v));
        if (is_true(v)) { set_true(e); }
        else if (is_false(v)) { set_false(e); }
        else {
            TRACE(old_spacer, tout << "not inherited:\n" << mk_pp(e, m) << "\n" << mk_pp(v, m) << "\n";);
            set_x(e);
        }
    } else if (m_arith.is_int_real(e)) {
        set_number(e, get_number(v));
    } else if (m.is_value(v)) {
        set_value(e, v);
    } else if (m_values.find(v, w)) {
        set_value(e, w);
    } else {
        TRACE(old_spacer, tout << "not inherited:\n" << mk_pp(e, m) << "\n" << mk_pp(v, m) << "\n";);
        set_x(e);
    }
}

void model_evaluator::eval_exprs(expr_ref_vector& es)
{
    model_ref mr(m_model);
    for (unsigned j = 0; j < es.size(); ++j) {
        if (m_array.is_as_array(es[j].get())) {
            es[j] = eval(mr, es[j].get());
        }
    }
}

bool model_evaluator::extract_array_func_interp(expr* a, vector<expr_ref_vector>& stores, expr_ref& else_case)
{
    SASSERT(m_array.is_array(a));

    TRACE(old_spacer, tout << mk_pp(a, m) << "\n";);
    while (m_array.is_store(a)) {
        expr_ref_vector store(m);
        store.append(to_app(a)->get_num_args() - 1, to_app(a)->get_args() + 1);
        eval_exprs(store);
        stores.push_back(store);
        a = to_app(a)->get_arg(0);
    }

    if (m_array.is_const(a)) {
        else_case = to_app(a)->get_arg(0);
        return true;
    }

    while (m_array.is_as_array(a)) {
        func_decl* f = m_array.get_as_array_func_decl(to_app(a));
        func_interp* g = m_model->get_func_interp(f);
        unsigned sz = g->num_entries();
        unsigned arity = f->get_arity();
        for (unsigned i = 0; i < sz; ++i) {
            expr_ref_vector store(m);
            func_entry const* fe = g->get_entry(i);
            store.append(arity, fe->get_args());
            store.push_back(fe->get_result());
            for (unsigned j = 0; j < store.size(); ++j) {
                if (!is_ground(store[j].get())) {
                    TRACE(old_spacer, tout << "could not extract array interpretation: " << mk_pp(a, m) << "\n" << mk_pp(store[j].get(), m) << "\n";);
                    return false;
                }
            }
            eval_exprs(store);
            stores.push_back(store);
        }
        else_case = g->get_else();
        if (!else_case) {
            TRACE(old_spacer, tout << "no else case " << mk_pp(a, m) << "\n";);
            return false;
        }
        if (!is_ground(else_case)) {
            TRACE(old_spacer, tout << "non-ground else case " << mk_pp(a, m) << "\n" << mk_pp(else_case, m) << "\n";);
            return false;
        }
        if (m_array.is_as_array(else_case)) {
            model_ref mr(m_model);
            else_case = eval(mr, else_case);
        }
        TRACE(old_spacer, tout << "else case: " << mk_pp(else_case, m) << "\n";);
        return true;
    }
    TRACE(old_spacer, tout << "no translation: " << mk_pp(a, m) << "\n";);

    return false;
}

/**
   best effort evaluator of extensional array equality.
*/
void model_evaluator::eval_array_eq(app* e, expr* arg1, expr* arg2)
{
    TRACE(old_spacer, tout << "array equality: " << mk_pp(e, m) << "\n";);
    expr_ref v1(m), v2(m);
    v1 = (*m_model)(arg1);
    v2 = (*m_model)(arg2);
    if (v1 == v2) {
        set_true(e);
        return;
    }
    sort* s = arg1->get_sort();
    sort* r = get_array_range(s);
    // give up evaluating finite domain/range arrays
    if (!r->is_infinite() && !r->is_very_big() && !s->is_infinite() && !s->is_very_big()) {
        TRACE(old_spacer, tout << "equality is unknown: " << mk_pp(e, m) << "\n";);
        set_x(e);
        return;
    }
    vector<expr_ref_vector> store;
    expr_ref else1(m), else2(m);
    if (!extract_array_func_interp(v1, store, else1) ||
            !extract_array_func_interp(v2, store, else2)) {
        TRACE(old_spacer, tout << "equality is unknown: " << mk_pp(e, m) << "\n";);
        set_x(e);
        return;
    }

    if (else1 != else2) {
        if (m.is_value(else1) && m.is_value(else2)) {
            TRACE(old_spacer, tout
                  << "defaults are different: " << mk_pp(e, m) << " "
                  << mk_pp(else1, m) << " " << mk_pp(else2, m) << "\n";);
            set_false(e);
        } else if (m_array.is_array(else1)) {
            eval_array_eq(e, else1, else2);
        } else {
            TRACE(old_spacer, tout << "equality is unknown: " << mk_pp(e, m) << "\n";);
            set_x(e);
        }
        return;
    }

    expr_ref s1(m), s2(m), w1(m), w2(m);
    expr_ref_vector args1(m), args2(m);
    args1.push_back(v1);
    args2.push_back(v2);
    for (unsigned i = 0; i < store.size(); ++i) {
        args1.resize(1);
        args2.resize(1);
        args1.append(store[i].size() - 1, store[i].data());
        args2.append(store[i].size() - 1, store[i].data());
        s1 = m_array.mk_select(args1.size(), args1.data());
        s2 = m_array.mk_select(args2.size(), args2.data());
        w1 = (*m_model)(s1);
        w2 = (*m_model)(s2);
        if (w1 == w2) {
            continue;
        }
        if (m.is_value(w1) && m.is_value(w2)) {
            TRACE(old_spacer, tout << "Equality evaluation: " << mk_pp(e, m) << "\n";
                  tout << mk_pp(s1, m) << " |-> " << mk_pp(w1, m) << "\n";
                  tout << mk_pp(s2, m) << " |-> " << mk_pp(w2, m) << "\n";);
            set_false(e);
        } else if (m_array.is_array(w1)) {
            eval_array_eq(e, w1, w2);
            if (is_true(e)) {
                continue;
            }
        } else {
            TRACE(old_spacer, tout << "equality is unknown: " << mk_pp(e, m) << "\n";);
            set_x(e);
        }
        return;
    }
    set_true(e);
}

void model_evaluator::eval_eq(app* e, expr* arg1, expr* arg2)
{
    if (arg1 == arg2) {
        set_true(e);
    } else if (m_array.is_array(arg1)) {
        eval_array_eq(e, arg1, arg2);
    } else if (is_x(arg1) || is_x(arg2)) {
        set_x(e);
    } else if (m.is_bool(arg1)) {
        bool val = is_true(arg1) == is_true(arg2);
        SASSERT(val == (is_false(arg1) == is_false(arg2)));
        if (val) {
            set_true(e);
        } else {
            set_false(e);
        }
    } else if (m_arith.is_int_real(arg1)) {
        set_bool(e, get_number(arg1) == get_number(arg2));
    } else {
        expr* e1 = get_value(arg1);
        expr* e2 = get_value(arg2);
        if (m.is_value(e1) && m.is_value(e2)) {
            set_bool(e, e1 == e2);
        } else if (e1 == e2) {
            set_bool(e, true);
        } else {
            TRACE(old_spacer, tout << "not value equal:\n" << mk_pp(e1, m) << "\n" << mk_pp(e2, m) << "\n";);
            set_x(e);
        }
    }
}

void model_evaluator::eval_basic(app* e)
{
    expr* arg1 = nullptr, *arg2 = nullptr;
    expr *argCond = nullptr, *argThen = nullptr, *argElse = nullptr, *arg = nullptr;
    bool has_x = false;
    unsigned arity = e->get_num_args();
    switch (e->get_decl_kind()) {
    case OP_AND:
        for (unsigned j = 0; j < arity; ++j) {
            expr * arg = e->get_arg(j);
            if (is_false(arg)) {
                set_false(e);
                return;
            } else if (is_x(arg)) {
                has_x = true;
            } else {
                SASSERT(is_true(arg));
            }
        }
        if (has_x) {
            set_x(e);
        } else {
            set_true(e);
        }
        break;
    case OP_OR:
        for (unsigned j = 0; j < arity; ++j) {
            expr * arg = e->get_arg(j);
            if (is_true(arg)) {
                set_true(e);
                return;
            } else if (is_x(arg)) {
                has_x = true;
            } else {
                SASSERT(is_false(arg));
            }
        }
        if (has_x) {
            set_x(e);
        } else {
            set_false(e);
        }
        break;
    case OP_NOT:
        VERIFY(m.is_not(e, arg));
        if (is_true(arg)) {
            set_false(e);
        } else if (is_false(arg)) {
            set_true(e);
        } else {
            SASSERT(is_x(arg));
            set_x(e);
        }
        break;
    case OP_IMPLIES:
        VERIFY(m.is_implies(e, arg1, arg2));
        if (is_false(arg1) || is_true(arg2)) {
            set_true(e);
        } else if (arg1 == arg2) {
            set_true(e);
        } else if (is_true(arg1) && is_false(arg2)) {
            set_false(e);
        } else {
            SASSERT(is_x(arg1) || is_x(arg2));
            set_x(e);
        }
        break;
    case OP_XOR:
        VERIFY(m.is_xor(e, arg1, arg2));
        eval_eq(e, arg1, arg2);
        if (is_false(e)) { set_true(e); }
        else if (is_true(e)) { set_false(e); }
        break;
    case OP_ITE:
        VERIFY(m.is_ite(e, argCond, argThen, argElse));
        if (is_true(argCond)) {
            inherit_value(e, argThen);
        } else if (is_false(argCond)) {
            inherit_value(e, argElse);
        } else if (argThen == argElse) {
            inherit_value(e, argThen);
        } else if (m.is_bool(e)) {
            SASSERT(is_x(argCond));
            if (is_x(argThen) || is_x(argElse)) {
                set_x(e);
            } else if (is_true(argThen) == is_true(argElse)) {
                inherit_value(e, argThen);
            } else {
                set_x(e);
            }
        } else {
            set_x(e);
        }
        break;
    case OP_TRUE:
        set_true(e);
        break;
    case OP_FALSE:
        set_false(e);
        break;
    case OP_EQ:
        VERIFY(m.is_eq(e, arg1, arg2));
        eval_eq(e, arg1, arg2);
        break;
    case OP_DISTINCT: {
        vector<rational> values;
        for (unsigned i = 0; i < arity; ++i) {
            expr* arg = e->get_arg(i);
            if (is_x(arg)) {
                set_x(e);
                return;
            }
            values.push_back(get_number(arg));
        }
        std::sort(values.begin(), values.end());
        for (unsigned i = 0; i + 1 < values.size(); ++i) {
            if (values[i] == values[i + 1]) {
                set_false(e);
                return;
            }
        }
        set_true(e);
        break;
    }
    default:
        IF_VERBOSE(0, verbose_stream() << "Term not handled " << mk_pp(e, m) << "\n";);
        UNREACHABLE();
    }
}

void model_evaluator::eval_fmls(ptr_vector<expr> const& formulas)
{
    ptr_vector<expr> todo(formulas);

    while (!todo.empty()) {
        expr * curr_e = todo.back();

        if (!is_app(curr_e)) {
            todo.pop_back();
            continue;
        }
        app * curr = to_app(curr_e);

        if (!is_unknown(curr)) {
            todo.pop_back();
            continue;
        }
        unsigned arity = curr->get_num_args();
        for (unsigned i = 0; i < arity; ++i) {
            if (is_unknown(curr->get_arg(i))) {
                todo.push_back(curr->get_arg(i));
            }
        }
        if (todo.back() != curr) {
            continue;
        }
        todo.pop_back();
        if (curr->get_family_id() == m_arith.get_family_id()) {
            eval_arith(curr);
        } else if (curr->get_family_id() == m.get_basic_family_id()) {
            eval_basic(curr);
        } else {
            expr_ref vl(m);
            vl = eval(m_model, curr);
            assign_value(curr, vl);
        }

        IF_VERBOSE(35, verbose_stream() << "assigned " << mk_pp(curr_e, m)
                   << (is_true(curr_e) ? "true" : is_false(curr_e) ? "false" : "unknown") << "\n";);
        SASSERT(!is_unknown(curr));
    }
}

bool model_evaluator::check_model(ptr_vector<expr> const& formulas)
{
    eval_fmls(formulas);
    bool has_x = false;
    for (unsigned i = 0; i < formulas.size(); ++i) {
        expr * form = formulas[i];
        SASSERT(!is_unknown(form));
        TRACE(spacer_verbose,
              tout << "formula is " << (is_true(form) ? "true" : is_false(form) ? "false" : "unknown") << "\n" << mk_pp(form, m) << "\n";);

        if (is_false(form)) {
            IF_VERBOSE(0, verbose_stream() << "formula false in model: " << mk_pp(form, m) << "\n";);
            UNREACHABLE();
        }
        if (is_x(form)) {
            IF_VERBOSE(0, verbose_stream() << "formula undetermined in model: " << mk_pp(form, m) << "\n";);
            TRACE(old_spacer, model_smt2_pp(tout, m, *m_model, 0););
            has_x = true;
        }
    }
    return !has_x;
}

expr_ref model_evaluator::eval_heavy(const model_ref& model, expr* fml)
{
    expr_ref result(model->get_manager());

    setup_model(model);
    ptr_vector<expr> fmls;
    fmls.push_back(fml);
    eval_fmls(fmls);
    if (is_false(fml)) {
        result = m.mk_false();
    } else if (is_true(fml) || is_x(fml)) {
        result = m.mk_true();
    } else if (m_arith.is_int_real(fml)) {
        result = m_arith.mk_numeral(get_number(fml), m_arith.is_int(fml));
    } else {
        result = get_value(fml);
    }
    reset();

    return result;
}

expr_ref model_evaluator::eval(const model_ref& model, func_decl* d)
{
    SASSERT(d->get_arity() == 0);
    expr_ref result(m);
    if (m_array.is_array(d->get_range())) {
        expr_ref e(m);
        e = m.mk_const(d);
        result = eval(model, e);
    } else {
        result = model->get_const_interp(d);
    }
    return result;
}

expr_ref model_evaluator::eval(const model_ref& model, expr* e){
    m_model = model.get();
    model::scoped_model_completion _scm(m_model, true);
    expr_ref result = (*m_model)(e);
    if (m_array.is_array(e)) {
        vector<expr_ref_vector> stores;
        expr_ref_vector args(m);
        expr_ref else_case(m);
        if (extract_array_func_interp(result, stores, else_case)) {
            result = m_array.mk_const_array(e->get_sort(), else_case);
            while (!stores.empty() && stores.back().back() == else_case) {
                stores.pop_back();
            }
            for (unsigned i = stores.size(); i > 0;) {
                --i;
                args.resize(1);
                args[0] = result;
                args.append(stores[i]);
                result = m_array.mk_store(args);
            }
            return result;
        }
    }
    return result;
}


}
