refactor(frontends/lean): cleanup add_delayed_theorem method

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>

src/frontends/lean/decl_cmds.cpp

@@ -267,18 +267,9 @@ environment definition_cmd_core(parser & p, bool is_theorem, bool _is_opaque) {
     if (is_theorem) {
         if (p.num_threads() > 1) {
             // add as axiom, and create a task to prove the theorem
-            expr saved_type             = type;
+            p.add_delayed_theorem(env, real_n, ls, type, value);
-            expr saved_value            = value;
-            environment saved_env       = env;
-            local_level_decls saved_lls = p.get_local_level_decls();
             std::tie(type, new_ls) = p.elaborate_type(type);
             env = module::add(env, check(env, mk_axiom(real_n, append(ls, new_ls), type)));
-            p.add_delayed_theorem([=, &p]() {
-                    level_param_names new_ls;
-                    expr type, value;
-                    std::tie(type, value, new_ls) = p.elaborate_definition_at(saved_env, saved_lls, n, saved_type, saved_value);
-                    return check(saved_env, mk_theorem(real_n, append(ls, new_ls), type, value));
-                });
         } else {
             std::tie(type, value, new_ls) = p.elaborate_definition(n, type, value);
             env = module::add(env, check(env, mk_theorem(real_n, append(ls, new_ls), type, value)));

src/frontends/lean/parser.cpp

@@ -17,6 +17,7 @@ Author: Leonardo de Moura
 #include "kernel/replace_fn.h"
 #include "kernel/abstract.h"
 #include "kernel/instantiate.h"
+#include "kernel/type_checker.h"
 #include "library/parser_nested_exception.h"
 #include "library/aliases.h"
 #include "library/private.h"
@@ -1077,6 +1078,16 @@ bool parser::parse_commands() {
     return !m_found_errors;
 }
 
+void parser::add_delayed_theorem(environment const & env, name const & n, level_param_names const & ls, expr const & t, expr const & v) {
+    local_level_decls saved_lls = get_local_level_decls();
+    m_theorem_queue.add([=]() {
+            level_param_names new_ls;
+            expr type, value;
+            std::tie(type, value, new_ls) = elaborate_definition_at(env, saved_lls, n, t, v);
+            return check(env, mk_theorem(n, append(ls, new_ls), type, value));
+        });
+}
+
 bool parse_commands(environment & env, io_state & ios, std::istream & in, char const * strm_name, bool use_exceptions,
                     unsigned num_threads) {
     parser p(env, ios, in, strm_name, use_exceptions, num_threads);

src/frontends/lean/parser.h

@@ -162,7 +162,7 @@ public:
     expr mk_app(std::initializer_list<expr> const & args, pos_info const & p);
 
     unsigned num_threads() const { return m_num_threads; }
-    void add_delayed_theorem(std::function<certified_declaration()> const & fn) { m_theorem_queue.add(fn); }
+    void add_delayed_theorem(environment const & env, name const & n, level_param_names const & ls, expr const & t, expr const & v);
 
     /** \brief Read the next token. */
     void scan() { m_curr = m_scanner.scan(m_env); }