diff --git a/src/frontends/lean/CMakeLists.txt b/src/frontends/lean/CMakeLists.txt
index 9e3ce80564..9cc762dff5 100644
--- a/src/frontends/lean/CMakeLists.txt
+++ b/src/frontends/lean/CMakeLists.txt
@@ -7,4 +7,4 @@ pp.cpp structure_cmd.cpp structure_instance.cpp
 init_module.cpp type_util.cpp decl_attributes.cpp
 prenum.cpp print_cmd.cpp elaborator.cpp elaborator_exception.cpp
 match_expr.cpp local_context_adapter.cpp decl_util.cpp definition_cmds.cpp
-brackets.cpp tactic_notation.cpp info_manager.cpp json.cpp)
+brackets.cpp tactic_notation.cpp info_manager.cpp json.cpp tactic_evaluator.cpp)
diff --git a/src/frontends/lean/elaborator.cpp b/src/frontends/lean/elaborator.cpp
index d03691fadc..d58d6e4d59 100644
--- a/src/frontends/lean/elaborator.cpp
+++ b/src/frontends/lean/elaborator.cpp
@@ -31,15 +31,11 @@ Author: Leonardo de Moura
 #include "library/locals.h"
 #include "library/private.h"
 #include "library/attribute_manager.h"
-#include "library/module.h"
 #include "library/scoped_ext.h"
 #include "library/protected.h"
 #include "library/aliases.h"
-#include "library/vm/vm.h"
 #include "library/vm/vm_name.h"
 #include "library/vm/vm_expr.h"
-#include "library/compiler/rec_fn_macro.h"
-#include "library/compiler/vm_compiler.h"
 #include "library/tactic/kabstract.h"
 #include "library/tactic/tactic_state.h"
 #include "library/tactic/elaborate.h"
@@ -49,7 +45,7 @@ Author: Leonardo de Moura
 #include "frontends/lean/util.h"
 #include "frontends/lean/prenum.h"
 #include "frontends/lean/elaborator.h"
-#include "frontends/lean/tactic_notation.h"
+#include "frontends/lean/tactic_evaluator.h"
 #include "frontends/lean/structure_cmd.h"
 #include "frontends/lean/structure_instance.h"
 
@@ -2434,23 +2430,6 @@ void elaborator::synthesize_type_class_instances() {
     }
 }
 
-[[noreturn]] static void throw_unsolved_tactic_state(tactic_state const & ts, format const & fmt, expr const & ref) {
-    format msg = fmt + line() + format("state:") + line() + ts.pp();
-    throw elaborator_exception(ref, msg);
-}
-
-[[noreturn]] static void throw_unsolved_tactic_state(tactic_state const & ts, char const * msg, expr const & ref) {
-    throw_unsolved_tactic_state(ts, format(msg), ref);
-}
-
-void elaborator::add_tactic_state_info(tactic_state const & s, expr const & ref) {
-    if (!get_global_info_manager()) return;
-    pos_info_provider * pip = get_pos_info_provider();
-    if (!pip) return;
-    if (auto p = pip->get_pos_info(ref))
-        m_info.add_tactic_state_info(p->first, p->second, s);
-}
-
 tactic_state elaborator::mk_tactic_state_for(expr const & mvar) {
     metavar_context mctx = m_ctx.mctx();
     metavar_decl mdecl   = *mctx.get_metavar_decl(mvar);
@@ -2462,123 +2441,20 @@ tactic_state elaborator::mk_tactic_state_for(expr const & mvar) {
     return ::lean::mk_tactic_state_for(m_env, m_opts, mctx, lctx, type);
 }
 
-/* Apply the given tactic to the state 's'.
-   Report any errors detected during the process using position information associated with 'ref'. */
-tactic_state elaborator::execute_tactic(expr const & tactic, tactic_state const & s, expr const & ref) {
-    pos_info_provider * provider = get_pos_info_provider();
-    scope_traces_as_messages traces_as_messages(provider, ref);
-
-    /* Compile tactic into bytecode */
-    name tactic_name("_tactic");
-    expr tactic_type = mk_tactic_unit();
-    environment new_env = m_env;
-    bool use_conv_opt    = true;
-    bool is_trusted      = false;
-    auto cd = check(new_env, mk_definition(new_env, tactic_name, {}, tactic_type, tactic, use_conv_opt, is_trusted));
-    new_env = new_env.add(cd);
-    if (auto pos = provider->get_pos_info(tactic))
-        new_env = add_transient_decl_pos_info(new_env, tactic_name, *pos);
-    new_env = vm_compile(new_env, new_env.get(tactic_name));
-
-    /* Invoke tactic */
-    vm_state S(new_env, m_opts);
-    vm_state::profiler prof(S, m_opts);
-    vm_obj r = S.invoke(tactic_name, to_obj(s));
-    if (prof.enabled())
-        prof.get_snapshots().display(get_global_ios().get_regular_stream());
-
-    if (optional<tactic_state> new_s = is_tactic_success(r)) {
-        trace_elab(tout() << "tactic at " << pos_string_for(ref) << " succeeded\n";);
-        return *new_s;
-    } else if (optional<tactic_exception_info> ex = is_tactic_exception(S, r)) {
-        format fmt          = std::get<0>(*ex);
-        optional<expr> ref1 = std::get<1>(*ex);
-        tactic_state s1     = std::get<2>(*ex);
-        if (ref1 && provider && provider->get_pos_info(*ref1))
-            throw elaborator_exception(*ref1, fmt);
-        else
-            throw_unsolved_tactic_state(s1, fmt, ref);
-    } else {
-        lean_unreachable();
-    }
-}
-
-tactic_state elaborator::execute_begin_end_tactics(buffer<expr> const & tactics, tactic_state const & s, expr const & ref) {
-    lean_assert(!tactics.empty());
-    list<expr> gs = s.goals();
-    if (!gs) throw elaborator_exception(ref, "tactic failed, there are no goals to be solved");
-    tactic_state new_s = set_goals(s, to_list(head(gs)));
-    for (expr const & tactic : tactics) {
-        expr const & curr_ref = tactic;
-        trace_elab_debug(tout() << "executing tactic:\n" << tactic << "\n";);
-        if (is_begin_end_element(tactic)) {
-            add_tactic_state_info(new_s, curr_ref);
-            new_s = execute_tactic(get_annotation_arg(tactic), new_s, curr_ref);
-        } else if (is_begin_end_block(tactic)) {
-            buffer<expr> nested_tactics;
-            get_begin_end_block_elements(tactic, nested_tactics);
-            new_s = execute_begin_end_tactics(nested_tactics, new_s, curr_ref);
-        } else {
-            throw elaborator_exception(curr_ref, "ill-formed 'begin ... end' tactic block");
-        }
-    }
-    add_tactic_state_info(new_s, ref);
-    if (new_s.goals()) throw_unsolved_tactic_state(new_s, "tactic failed, there are unsolved goals", ref);
-    return set_goals(new_s, tail(gs));
-}
-
-/* Try to synthesize 'mvar' by executing a sequence of tactics.
-   This method is used to process `begin ... end` blocks. */
-void elaborator::invoke_begin_end_tactics(expr const & mvar, buffer<expr> const & tactics) {
-    expr const & ref   = mvar;
-    tactic_state s     = mk_tactic_state_for(mvar);
-    trace_elab(tout() << "initial tactic state\n" << s.pp_core() << "\n";);
-    tactic_state new_s = execute_begin_end_tactics(tactics, s, ref);
-    metavar_context mctx = new_s.mctx();
-    expr val             = mctx.instantiate_mvars(new_s.main());
-    if (has_expr_metavar(val)) {
-        throw_unsolved_tactic_state(new_s, "tactic failed, result contains meta-variables", ref);
-    }
-    mctx.assign(mvar, val);
-    m_env = new_s.env();
-    m_ctx.set_env(m_env);
-    m_ctx.set_mctx(mctx);
-}
-
-/* Try to synthesize 'mvar' by executing the given tactic.
-   This method is used to process `by tactic` expressions */
-void elaborator::invoke_atomic_tactic(expr const & mvar, expr const & tactic) {
-    expr const & ref = mvar;
-    tactic_state s       = mk_tactic_state_for(mvar);
-    add_tactic_state_info(s, ref);
-    /* Save information using tactic's position, ref is usually the `by` token position */
-    add_tactic_state_info(s, tactic);
-    trace_elab(tout() << "initial tactic state\n" << s.pp_core() << "\n";);
-    tactic_state new_s   = execute_tactic(tactic, s, ref);
-    if (new_s.goals())
-        throw_unsolved_tactic_state(new_s, "tactic failed, there are unsolved goals", ref);
-    metavar_context mctx = new_s.mctx();
-    expr val             = mctx.instantiate_mvars(new_s.main());
-    if (has_expr_metavar(val)) {
-        throw_unsolved_tactic_state(new_s, "tactic failed, result contains meta-variables", ref);
-    }
-    mctx.assign(mvar, val);
-    m_env = new_s.env();
-    m_ctx.set_env(m_env);
-    m_ctx.set_mctx(mctx);
-}
-
 void elaborator::invoke_tactic(expr const & mvar, expr const & tactic) {
-    expr const & ref = mvar;
-    /* Build initial state */
-    trace_elab(tout() << "executing tactic at " << pos_string_for(ref) << "\n";);
-    if (is_begin_end_block(tactic)) {
-        buffer<expr> tactics;
-        get_begin_end_block_elements(tactic, tactics);
-        invoke_begin_end_tactics(mvar, tactics);
-    } else {
-        invoke_atomic_tactic(mvar, tactic);
+    expr const & ref     = mvar;
+    tactic_state s       = mk_tactic_state_for(mvar);
+    tactic_state new_s   = tactic_evaluator(m_ctx, m_info, m_opts)(s, tactic, ref);
+
+    metavar_context mctx = new_s.mctx();
+    expr val             = mctx.instantiate_mvars(new_s.main());
+    if (has_expr_metavar(val)) {
+        throw_unsolved_tactic_state(new_s, "tactic failed, result contains meta-variables", ref);
     }
+    mctx.assign(mvar, val);
+    m_env = new_s.env();
+    m_ctx.set_env(m_env);
+    m_ctx.set_mctx(mctx);
 }
 
 void elaborator::synthesize_using_tactics() {
diff --git a/src/frontends/lean/tactic_evaluator.cpp b/src/frontends/lean/tactic_evaluator.cpp
new file mode 100644
index 0000000000..b98c2a75d1
--- /dev/null
+++ b/src/frontends/lean/tactic_evaluator.cpp
@@ -0,0 +1,169 @@
+/*
+Copyright (c) 2017 Microsoft Corporation. All rights reserved.
+Released under Apache 2.0 license as described in the file LICENSE.
+
+Author: Leonardo de Moura
+*/
+#include "kernel/type_checker.h"
+#include "library/module.h"
+#include "library/trace.h"
+#include "library/annotation.h"
+#include "library/scope_pos_info_provider.h"
+#include "library/vm/vm_list.h"
+#include "library/compiler/vm_compiler.h"
+#include "library/tactic/smt/smt_state.h"
+#include "frontends/lean/elaborator_exception.h"
+#include "frontends/lean/tactic_evaluator.h"
+#include "frontends/lean/tactic_notation.h"
+
+namespace lean {
+[[noreturn]] void throw_unsolved_tactic_state(tactic_state const & ts, format const & fmt, expr const & ref) {
+    format msg = fmt + line() + format("state:") + line() + ts.pp();
+    throw elaborator_exception(ref, msg);
+}
+
+[[noreturn]] void throw_unsolved_tactic_state(tactic_state const & ts, char const * msg, expr const & ref) {
+    throw_unsolved_tactic_state(ts, format(msg), ref);
+}
+
+/* Compile tactic into bytecode */
+environment tactic_evaluator::compile_tactic(name const & tactic_name, expr const & tactic) {
+    pos_info_provider * provider = get_pos_info_provider();
+    expr tactic_type     = m_ctx.infer(tactic);
+    environment new_env  = m_ctx.env();
+    bool use_conv_opt    = true;
+    bool is_trusted      = false;
+    auto cd = check(new_env, mk_definition(new_env, tactic_name, {}, tactic_type, tactic, use_conv_opt, is_trusted));
+    new_env = new_env.add(cd);
+    if (auto pos = provider->get_pos_info(tactic))
+        new_env = add_transient_decl_pos_info(new_env, tactic_name, *pos);
+    return vm_compile(new_env, new_env.get(tactic_name));
+}
+
+vm_obj tactic_evaluator::invoke_tactic(vm_state & S, name const & tactic_name, std::initializer_list<vm_obj> const & args) {
+    vm_state::profiler prof(S, m_opts);
+    vm_obj r = S.invoke(tactic_name, args);
+    if (prof.enabled())
+        prof.get_snapshots().display(get_global_ios().get_regular_stream());
+    return r;
+}
+
+void tactic_evaluator::add_tactic_state_info(tactic_state const & s, expr const & ref) {
+    if (!get_global_info_manager()) return;
+    pos_info_provider * pip = get_pos_info_provider();
+    if (!pip) return;
+    if (auto p = pip->get_pos_info(ref))
+        m_info.add_tactic_state_info(p->first, p->second, s);
+}
+
+static list<smt_goal> to_smt_state(vm_obj const & ss) {
+    return to_list<smt_goal>(ss, to_smt_goal);
+}
+
+void tactic_evaluator::add_smt_tactic_state_info(vm_obj const & ss, tactic_state const & /* ts */, expr const & ref) {
+    if (!get_global_info_manager()) return;
+    pos_info_provider * pip = get_pos_info_provider();
+    if (!pip) return;
+    if (auto p = pip->get_pos_info(ref)) {
+        list<smt_goal> _ss = to_smt_state(ss);
+        // m_info.add_smt_tactic_state_info(p->first, p->second, _ss, ts);
+    }
+}
+
+static void process_failure(vm_state & S, vm_obj const & r, expr const & ref) {
+    pos_info_provider * provider = get_pos_info_provider();
+    if (optional<tactic_exception_info> ex = is_tactic_exception(S, r)) {
+        format fmt          = std::get<0>(*ex);
+        optional<expr> ref1 = std::get<1>(*ex);
+        tactic_state s1     = std::get<2>(*ex);
+        if (ref1 && provider && provider->get_pos_info(*ref1))
+            throw elaborator_exception(*ref1, fmt);
+        else
+            throw_unsolved_tactic_state(s1, fmt, ref);
+    }
+}
+
+tactic_state tactic_evaluator::execute_tactic(expr const & tactic, tactic_state const & s, expr const & ref) {
+    pos_info_provider * provider = get_pos_info_provider();
+    scope_traces_as_messages traces_as_messages(provider, ref);
+
+    name tactic_name("_tactic");
+    environment new_env = compile_tactic(tactic_name, tactic);
+
+    vm_state S(new_env, m_opts);
+    vm_obj r = invoke_tactic(S, tactic_name, {to_obj(s)});
+
+    if (optional<tactic_state> new_s = is_tactic_success(r)) {
+        return *new_s;
+    }
+    process_failure(S, r, ref);
+    lean_unreachable();
+}
+
+pair<vm_obj, tactic_state> tactic_evaluator::excute_smt_tactic(expr const & tactic, vm_obj const & ss, tactic_state const & ts, expr const & ref) {
+    pos_info_provider * provider = get_pos_info_provider();
+    scope_traces_as_messages traces_as_messages(provider, ref);
+
+    name tactic_name("_smt_tactic");
+    environment new_env = compile_tactic(tactic_name, tactic);
+
+    vm_state S(new_env, m_opts);
+    vm_obj r = invoke_tactic(S, tactic_name, {ss, to_obj(ts)});
+
+    if (is_tactic_result_success(r)) {
+        vm_obj new_ss       = cfield(get_tactic_result_value(r), 1);
+        tactic_state new_ts = to_tactic_state(get_tactic_result_state(r));
+        return mk_pair(new_ss, new_ts);
+    }
+    process_failure(S, r, ref);
+    lean_unreachable();
+}
+
+tactic_state tactic_evaluator::execute_begin_end(tactic_state const & s, buffer<expr> const & tactics, expr const & ref) {
+    /* TODO(Leo): check if it is a begin[smt] ... end block */
+    lean_assert(!tactics.empty());
+    list<expr> gs = s.goals();
+    if (!gs) throw elaborator_exception(ref, "tactic failed, there are no goals to be solved");
+    tactic_state new_s = set_goals(s, to_list(head(gs)));
+    for (expr const & tactic : tactics) {
+        expr const & curr_ref = tactic;
+        if (is_begin_end_element(tactic)) {
+            add_tactic_state_info(new_s, curr_ref);
+            new_s = execute_tactic(get_annotation_arg(tactic), new_s, curr_ref);
+        } else if (is_begin_end_block(tactic)) {
+            buffer<expr> nested_tactics;
+            get_begin_end_block_elements(tactic, nested_tactics);
+            new_s = execute_begin_end(new_s, nested_tactics, curr_ref);
+        } else {
+            throw elaborator_exception(curr_ref, "ill-formed 'begin ... end' tactic block");
+        }
+    }
+    add_tactic_state_info(new_s, ref);
+    if (new_s.goals()) throw_unsolved_tactic_state(new_s, "tactic failed, there are unsolved goals", ref);
+    return set_goals(new_s, tail(gs));
+}
+
+tactic_state tactic_evaluator::execute_atomic(tactic_state const & s, expr const & tactic, expr const & ref) {
+    add_tactic_state_info(s, ref);
+    /* Save information using tactic's position, ref is usually the `by` token position */
+    add_tactic_state_info(s, tactic);
+    tactic_state new_s = execute_tactic(tactic, s, ref);
+    if (new_s.goals())
+        throw_unsolved_tactic_state(new_s, "tactic failed, there are unsolved goals", ref);
+    return new_s;
+}
+
+tactic_state tactic_evaluator::operator()(tactic_state const & s, expr const & tactic, expr const & ref) {
+    if (is_begin_end_block(tactic)) {
+        buffer<expr> tactics;
+        get_begin_end_block_elements(tactic, tactics);
+        return execute_begin_end(s, tactics, ref);
+    } else {
+        return execute_atomic(s, tactic, ref);
+    }
+}
+
+tactic_evaluator::tactic_evaluator(type_context & ctx, info_manager & info, options const & opts):
+    m_ctx(ctx), m_info(info), m_opts(opts) {
+}
+}
diff --git a/src/frontends/lean/tactic_evaluator.h b/src/frontends/lean/tactic_evaluator.h
new file mode 100644
index 0000000000..c66e67a920
--- /dev/null
+++ b/src/frontends/lean/tactic_evaluator.h
@@ -0,0 +1,36 @@
+/*
+Copyright (c) 2017 Microsoft Corporation. All rights reserved.
+Released under Apache 2.0 license as described in the file LICENSE.
+
+Author: Leonardo de Moura
+*/
+#pragma once
+#include "library/tactic/tactic_state.h"
+#include "frontends/lean/info_manager.h"
+
+namespace lean {
+[[noreturn]] void throw_unsolved_tactic_state(tactic_state const & ts, format const & fmt, expr const & ref);
+[[noreturn]] void throw_unsolved_tactic_state(tactic_state const & ts, char const * msg, expr const & ref);
+
+class tactic_evaluator {
+    type_context &  m_ctx;
+    info_manager &  m_info;
+    options const & m_opts;
+
+    environment compile_tactic(name const & tactic_name, expr const & tactic);
+    vm_obj invoke_tactic(vm_state & S, name const & tactic_name, std::initializer_list<vm_obj> const & args);
+
+    void add_tactic_state_info(tactic_state const & s, expr const & ref);
+    void add_smt_tactic_state_info(vm_obj const & ss, tactic_state const & ts, expr const & ref);
+
+    tactic_state execute_tactic(expr const & tactic, tactic_state const & s, expr const & ref);
+    pair<vm_obj, tactic_state> excute_smt_tactic(expr const & tactic, vm_obj const & ss, tactic_state const & ts, expr const & ref);
+
+    tactic_state execute_begin_end(tactic_state const & s, buffer<expr> const & tactics, expr const & ref);
+    tactic_state execute_atomic(tactic_state const & s, expr const & tactic, expr const & ref);
+public:
+    tactic_evaluator(type_context & ctx, info_manager & info, options const & opts);
+
+    tactic_state operator()(tactic_state const & s, expr const & tactic, expr const & ref);
+};
+}
diff --git a/src/library/tactic/smt/smt_state.cpp b/src/library/tactic/smt/smt_state.cpp
index 30f65bfb0a..fffb5a3006 100644
--- a/src/library/tactic/smt/smt_state.cpp
+++ b/src/library/tactic/smt/smt_state.cpp
@@ -110,23 +110,6 @@ vm_obj to_obj(smt_goal const & s) {
     return mk_vm_external(new (get_vm_allocator().allocate(sizeof(vm_smt_goal))) vm_smt_goal(s));
 }
 
-bool is_tactic_result_exception(vm_obj const & a) {
-    return is_constructor(a) && cidx(a) == 1;
-}
-
-vm_obj mk_tactic_result(vm_obj const & a, vm_obj const & s) {
-    lean_assert(is_tactic_state(s));
-    return mk_vm_constructor(0, a, s);
-}
-
-vm_obj get_tactic_result_value(vm_obj const & r) {
-    return cfield(r, 0);
-}
-
-vm_obj get_tactic_result_state(vm_obj const & r) {
-    return cfield(r, 1);
-}
-
 vm_obj tactic_result_to_smt_tactic_result(vm_obj const & r, vm_obj const & ss) {
     return mk_tactic_result(mk_vm_pair(get_tactic_result_value(r), ss), get_tactic_result_state(r));
 }
diff --git a/src/library/tactic/smt/smt_state.h b/src/library/tactic/smt/smt_state.h
index 3e53fbe6a1..6a665d5e71 100644
--- a/src/library/tactic/smt/smt_state.h
+++ b/src/library/tactic/smt/smt_state.h
@@ -62,6 +62,10 @@ public:
     }
 };
 
+bool is_smt_goal(vm_obj const & o);
+smt_goal const & to_smt_goal(vm_obj const & o);
+vm_obj to_obj(smt_goal const & s);
+
 void initialize_smt_state();
 void finalize_smt_state();
 }
diff --git a/src/library/tactic/tactic_state.cpp b/src/library/tactic/tactic_state.cpp
index c97b8f2697..8fd6e80595 100644
--- a/src/library/tactic/tactic_state.cpp
+++ b/src/library/tactic/tactic_state.cpp
@@ -256,6 +256,29 @@ optional<tactic_exception_info> is_tactic_exception(vm_state & S, vm_obj const &
     }
 }
 
+vm_obj mk_tactic_result(vm_obj const & a, vm_obj const & s) {
+    lean_assert(is_tactic_state(s));
+    return mk_vm_constructor(0, a, s);
+}
+
+bool is_tactic_result_exception(vm_obj const & r) {
+    return is_constructor(r) && cidx(r) == 1;
+}
+
+bool is_tactic_result_success(vm_obj const & r) {
+    return is_constructor(r) && cidx(r) == 0;
+}
+
+vm_obj get_tactic_result_value(vm_obj const & r) {
+    lean_assert(is_tactic_result_success(r));
+    return cfield(r, 0);
+}
+
+vm_obj get_tactic_result_state(vm_obj const & r) {
+    lean_assert(is_tactic_result_success(r));
+    return cfield(r, 1);
+}
+
 vm_obj mk_tactic_success(vm_obj const & a, tactic_state const & s) {
     return mk_vm_constructor(0, a, to_obj(s));
 }
diff --git a/src/library/tactic/tactic_state.h b/src/library/tactic/tactic_state.h
index 3c11fc0060..f9cbcdc55e 100644
--- a/src/library/tactic/tactic_state.h
+++ b/src/library/tactic/tactic_state.h
@@ -108,6 +108,12 @@ vm_obj to_obj(tactic_state const & s);
 transparency_mode to_transparency_mode(vm_obj const & o);
 vm_obj to_obj(transparency_mode m);
 
+bool is_tactic_result_exception(vm_obj const & r);
+bool is_tactic_result_success(vm_obj const & r);
+vm_obj get_tactic_result_value(vm_obj const & r);
+vm_obj get_tactic_result_state(vm_obj const & r);
+vm_obj mk_tactic_result(vm_obj const & a, vm_obj const & s);
+
 vm_obj mk_tactic_success(vm_obj const & a, tactic_state const & s);
 vm_obj mk_tactic_success(tactic_state const & s);
 vm_obj mk_tactic_exception(vm_obj const & fn, tactic_state const & s);