diff --git a/include/xo/reader/parserstatemachine.hpp b/include/xo/reader/parserstatemachine.hpp
index 060ec841..c5222194 100644
--- a/include/xo/reader/parserstatemachine.hpp
+++ b/include/xo/reader/parserstatemachine.hpp
@@ -26,6 +26,7 @@ namespace xo {
                 : p_stack_{p_stack}, p_emit_expr_{p_emit_expr} {}
 
             std::unique_ptr<exprstate> pop_exprstate();
+            exprstate & top_exprstate();
 
         public:
             exprstatestack * p_stack_;
diff --git a/src/reader/define_xs.cpp b/src/reader/define_xs.cpp
index a4d9f1b6..4672bc96 100644
--- a/src/reader/define_xs.cpp
+++ b/src/reader/define_xs.cpp
@@ -20,7 +20,7 @@ namespace xo {
             auto p_stack = p_psm->p_stack_;
 
             p_stack->push_exprstate(define_xs::make());
-            p_stack->top_exprstate().on_def_token(token_type::def(), p_psm);
+            p_psm->top_exprstate().on_def_token(token_type::def(), p_psm);
         }
 
         define_xs::define_xs(rp<DefineExprAccess> def_expr)
@@ -132,8 +132,6 @@ namespace xo {
             constexpr bool c_debug_flag = true;
             scope log(XO_DEBUG(c_debug_flag));
 
-            auto p_stack = p_psm->p_stack_;
-
             //constexpr const char * self_name = "exprstate::on_semicolon";
 
             if (this->defxs_type_ == defexprstatetype::def_6) {
@@ -141,7 +139,7 @@ namespace xo {
 
                 std::unique_ptr<exprstate> self = p_psm->pop_exprstate();
 
-                p_stack->top_exprstate().on_expr(expr, p_psm);
+                p_psm->top_exprstate().on_expr(expr, p_psm);
             } else {
                 exprstate::on_semicolon_token(tk, p_psm);
             }
diff --git a/src/reader/expect_expr_xs.cpp b/src/reader/expect_expr_xs.cpp
index 538bd45c..bdd66b1a 100644
--- a/src/reader/expect_expr_xs.cpp
+++ b/src/reader/expect_expr_xs.cpp
@@ -46,7 +46,7 @@ namespace xo {
 
             /* push lparen_0 to remember to look for subsequent rightparen. */
             lambda_xs::start(p_stack, p_emit_expr);
-            //p_stack->top_exprstate().on_lambda_token(tk, p_stack, p_emit_expr);
+            //p_psm->top_exprstate().on_lambda_token(tk, p_stack, p_emit_expr);
             //p_stack->push_exprstate(expect_expr_xs::expect_rhs_expression());
         }
 
@@ -92,7 +92,7 @@ namespace xo {
 
 #ifdef LATER
             p_psm->pop_exprstate();
-            p_stack->top_exprstate().on_symbol(tk.text(),
+            p_psm->top_exprstate().on_symbol(tk.text(),
                                                p_stack, p_emit_expr);
 #endif
             return;
@@ -127,11 +127,9 @@ namespace xo {
             log && log(xtag("exstype", this->exs_type_),
                        xtag("expr", expr));
 
-            auto p_stack = p_psm->p_stack_;
-
             std::unique_ptr<exprstate> self = p_psm->pop_exprstate();
 
-            p_stack->top_exprstate().on_expr(expr, p_psm);
+            p_psm->top_exprstate().on_expr(expr, p_psm);
         } /*on_expr*/
 
     } /*namespace scm*/
diff --git a/src/reader/expect_formal_arglist_xs.cpp b/src/reader/expect_formal_arglist_xs.cpp
index 1dc27429..2f9f0fce 100644
--- a/src/reader/expect_formal_arglist_xs.cpp
+++ b/src/reader/expect_formal_arglist_xs.cpp
@@ -93,12 +93,10 @@ namespace xo {
         expect_formal_arglist_xs::on_rightparen_token(const token_type & tk,
                                                       parserstatemachine * p_psm)
         {
-            auto p_stack = p_psm->p_stack_;
-
             if (farglxs_type_ == formalarglstatetype::argl_1b) {
                 std::unique_ptr<exprstate> self = p_psm->pop_exprstate();
 
-                p_stack->top_exprstate().on_formal_arglist(this->argl_, p_psm);
+                p_psm->top_exprstate().on_formal_arglist(this->argl_, p_psm);
             } else {
                 exprstate::on_rightparen_token(tk, p_psm);
             }
diff --git a/src/reader/expect_formal_xs.cpp b/src/reader/expect_formal_xs.cpp
index 2cb2e9be..7bd8773d 100644
--- a/src/reader/expect_formal_xs.cpp
+++ b/src/reader/expect_formal_xs.cpp
@@ -80,8 +80,6 @@ namespace xo {
         expect_formal_xs::on_typedescr(TypeDescr td,
                                        parserstatemachine * p_psm)
         {
-            auto p_stack = p_psm->p_stack_;
-
             if (this->formalxs_type_ == formalstatetype::formal_2) {
                 this->result_.assign_td(td);
 
@@ -90,7 +88,7 @@ namespace xo {
                 rp<Variable> var = Variable::make(result_.name(),
                                                   result_.td());
 
-                p_stack->top_exprstate().on_formal(var, p_psm);
+                p_psm->top_exprstate().on_formal(var, p_psm);
             } else {
                 exprstate::on_typedescr(td, p_psm);
             }
diff --git a/src/reader/expect_symbol_xs.cpp b/src/reader/expect_symbol_xs.cpp
index 77219efb..3c8bfd2d 100644
--- a/src/reader/expect_symbol_xs.cpp
+++ b/src/reader/expect_symbol_xs.cpp
@@ -28,15 +28,13 @@ namespace xo {
         expect_symbol_xs::on_symbol_token(const token_type & tk,
                                           parserstatemachine * p_psm)
         {
-            auto p_stack = p_psm->p_stack_;
-
             /* have to do pop first, before sending symbol to
              * the o.g. symbol-requester
              */
             std::unique_ptr<exprstate> self = p_psm->pop_exprstate();
 
 
-            p_stack->top_exprstate().on_symbol(tk.text(), p_psm);
+            p_psm->top_exprstate().on_symbol(tk.text(), p_psm);
             return;
         }
     } /*namespace scm*/
diff --git a/src/reader/expect_type_xs.cpp b/src/reader/expect_type_xs.cpp
index 9bbf4e18..f8efd265 100644
--- a/src/reader/expect_type_xs.cpp
+++ b/src/reader/expect_type_xs.cpp
@@ -33,8 +33,6 @@ namespace xo {
         {
             const char * c_self_name = "expect_type_xs::on_symbol_token";
 
-            auto p_stack = p_psm->p_stack_;
-
             TypeDescr td = nullptr;
 
             /* TODO: replace with typetable lookup */
@@ -59,7 +57,7 @@ namespace xo {
             }
 
             std::unique_ptr<exprstate> self = p_psm->pop_exprstate();
-            p_stack->top_exprstate().on_typedescr(td, p_psm);
+            p_psm->top_exprstate().on_typedescr(td, p_psm);
         }
     } /*namespace scm*/
 } /*namespace xo*/
diff --git a/src/reader/exprstate.cpp b/src/reader/exprstate.cpp
index 9a2917e0..9721ede2 100644
--- a/src/reader/exprstate.cpp
+++ b/src/reader/exprstate.cpp
@@ -73,9 +73,7 @@ namespace xo {
             constexpr bool c_debug_flag = true;
             scope log(XO_DEBUG(c_debug_flag));
 
-            auto p_stack = p_psm->p_stack_;
-
-            log && log(xtag("exstype", p_stack->top_exprstate().exs_type()));
+            log && log(xtag("exstype", p_psm->top_exprstate().exs_type()));
 
             constexpr const char * c_self_name = "exprstate::on_symbol_token";
 
@@ -91,10 +89,8 @@ namespace xo {
             constexpr bool c_debug_flag = true;
             scope log(XO_DEBUG(c_debug_flag));
 
-            auto p_stack = p_psm->p_stack_;
-
             log && log(xtag("exstype",
-                            p_stack->top_exprstate().exs_type()));
+                            p_psm->top_exprstate().exs_type()));
 
             constexpr const char * c_self_name = "exprstate::on_typedescr";
 
@@ -113,10 +109,8 @@ namespace xo {
             constexpr bool c_debug_flag = true;
             scope log(XO_DEBUG(c_debug_flag));
 
-            auto p_stack = p_psm->p_stack_;
-
             log && log(xtag("exstype",
-                            p_stack->top_exprstate().exs_type()));
+                            p_psm->top_exprstate().exs_type()));
 
             constexpr const char * c_self_name = "exprstate::on_formal";
 
@@ -135,10 +129,8 @@ namespace xo {
             constexpr bool c_debug_flag = true;
             scope log(XO_DEBUG(c_debug_flag));
 
-            auto p_stack = p_psm->p_stack_;
-
             log && log(xtag("exstype",
-                            p_stack->top_exprstate().exs_type()));
+                            p_psm->top_exprstate().exs_type()));
 
             constexpr const char * c_self_name = "exprstate::on_formal_arglist";
 
diff --git a/src/reader/lambda_xs.cpp b/src/reader/lambda_xs.cpp
index 80aac681..1ad6f401 100644
--- a/src/reader/lambda_xs.cpp
+++ b/src/reader/lambda_xs.cpp
@@ -74,8 +74,6 @@ namespace xo {
         lambda_xs::on_semicolon_token(const token_type & tk,
                                       parserstatemachine * p_psm)
         {
-            auto p_stack = p_psm->p_stack_;
-
             if (lmxs_type_ == lambdastatetype::lm_3) {
                 /* done! */
 
@@ -85,8 +83,8 @@ namespace xo {
 
                 rp<Lambda> lm = Lambda::make(name, argl_, body_);
 
-                p_stack->top_exprstate().on_expr(lm, p_psm);
-                p_stack->top_exprstate().on_semicolon_token(tk, p_psm);
+                p_psm->top_exprstate().on_expr(lm, p_psm);
+                p_psm->top_exprstate().on_semicolon_token(tk, p_psm);
 
                 return;
             }
diff --git a/src/reader/paren_xs.cpp b/src/reader/paren_xs.cpp
index c39a89cb..d1d9535c 100644
--- a/src/reader/paren_xs.cpp
+++ b/src/reader/paren_xs.cpp
@@ -80,9 +80,7 @@ namespace xo {
             constexpr bool c_debug_flag = true;
             scope log(XO_DEBUG(c_debug_flag));
 
-            auto p_stack = p_psm->p_stack_;
-
-            log && log(xtag("exstype", p_stack->top_exprstate().exs_type()));
+            log && log(xtag("exstype", p_psm->top_exprstate().exs_type()));
 
             //constexpr const char * self_name = "paren_xs::on_symbol";
 
@@ -152,11 +150,9 @@ namespace xo {
             if (this->parenxs_type_ == parenexprstatetype::lparen_1) {
                 rp<Expression> expr = this->gen_expr_;
 
-                auto p_stack = p_psm->p_stack_;
-
                 std::unique_ptr<exprstate> self = p_psm->pop_exprstate();
 
-                p_stack->top_exprstate().on_expr(expr, p_psm);
+                p_psm->top_exprstate().on_expr(expr, p_psm);
             }
         }
 
diff --git a/src/reader/progress_xs.cpp b/src/reader/progress_xs.cpp
index 3431e689..6f62f853 100644
--- a/src/reader/progress_xs.cpp
+++ b/src/reader/progress_xs.cpp
@@ -199,13 +199,11 @@ namespace xo {
             constexpr bool c_debug_flag = true;
             scope log(XO_DEBUG(c_debug_flag));
 
-            auto p_stack = p_psm->p_stack_;
-
             rp<Expression> expr = this->assemble_expr();
 
             std::unique_ptr<exprstate> self = p_psm->pop_exprstate();
 
-            p_stack->top_exprstate().on_expr(expr, p_psm);
+            p_psm->top_exprstate().on_expr(expr, p_psm);
 
             /* control here on input like:
              *   (1.234;
@@ -222,7 +220,7 @@ namespace xo {
              * f. now deliver semicolon;  [lparen_1] rejects
              */
 
-            p_stack->top_exprstate().on_semicolon_token(tk, p_psm);
+            p_psm->top_exprstate().on_semicolon_token(tk, p_psm);
         }
 
         void
@@ -283,10 +281,10 @@ namespace xo {
 
              log && log(xtag("stack", p_stack));
 
-             p_stack->top_exprstate().on_expr(expr, p_psm);
+             p_psm->top_exprstate().on_expr(expr, p_psm);
 
              /* now deliver rightparen */
-             p_stack->top_exprstate().on_rightparen_token(tk, p_psm);
+             p_psm->top_exprstate().on_rightparen_token(tk, p_psm);
          }
 
         namespace {