diff --git a/include/xo/reader2/DExprSeqState.hpp b/include/xo/reader2/DExprSeqState.hpp
index 83448b5e..150303c6 100644
--- a/include/xo/reader2/DExprSeqState.hpp
+++ b/include/xo/reader2/DExprSeqState.hpp
@@ -41,16 +41,17 @@ namespace xo {
             using Super = DSyntaxStateMachine<DExprSeqState>;
             using TypeDescr = xo::reflect::TypeDescr;
             using AAllocator = xo::mm::AAllocator;
+            using DArena = xo::mm::DArena;
             using ppindentinfo = xo::print::ppindentinfo;
 
         public:
             explicit DExprSeqState(exprseqtype ty);
 
             /** start interactive top-level session **/
-            static void establish_interactive(obj<AAllocator> mm,
+            static void establish_interactive(DArena & mm,
                                               ParserStateMachine * p_psm);
             /** start non-interactive top-level session **/
-            static void establish_batch(obj<AAllocator> mm,
+            static void establish_batch(DArena & mm,
                                         ParserStateMachine * p_psm);
 
         public:
diff --git a/src/reader2/DExprSeqState.cpp b/src/reader2/DExprSeqState.cpp
index 1d9b38a3..8261b506 100644
--- a/src/reader2/DExprSeqState.cpp
+++ b/src/reader2/DExprSeqState.cpp
@@ -35,6 +35,7 @@ namespace xo {
     using xo::scm::DFloat;
     using xo::mm::AGCObject;
     using xo::mm::AAllocator;
+    using xo::mm::DArena;
     using xo::facet::with_facet;
     using xo::reflect::typeseq;
 
@@ -59,7 +60,7 @@ namespace xo {
 
         namespace {
             obj<ASyntaxStateMachine>
-            make_exprseq_ssm(obj<AAllocator> mm,
+            make_exprseq_ssm(DArena & mm,
                              exprseqtype seqtype)
             {
                 void * mem = mm.alloc(typeseq::id<DExprSeqState>(),
@@ -67,12 +68,12 @@ namespace xo {
 
                 DExprSeqState * ssm = new (mem) DExprSeqState(seqtype);
 
-                return with_facet<ASyntaxStateMachine>::mkobj(ssm);
+                return obj<ASyntaxStateMachine,DExprSeqState>(ssm);
             }
         }
 
         void
-        DExprSeqState::establish_interactive(obj<AAllocator> mm,
+        DExprSeqState::establish_interactive(DArena & mm,
                                              ParserStateMachine * p_psm)
         {
             p_psm->establish_toplevel_ssm(make_exprseq_ssm
@@ -81,7 +82,7 @@ namespace xo {
         }
 
         void
-        DExprSeqState::establish_batch(obj<AAllocator> mm,
+        DExprSeqState::establish_batch(DArena & mm,
                                        ParserStateMachine * p_psm)
         {
             p_psm->establish_toplevel_ssm(make_exprseq_ssm
diff --git a/src/reader2/SchematikaParser.cpp b/src/reader2/SchematikaParser.cpp
index 37ebdd05..3a30b18a 100644
--- a/src/reader2/SchematikaParser.cpp
+++ b/src/reader2/SchematikaParser.cpp
@@ -65,14 +65,14 @@ namespace xo {
         void
         SchematikaParser::begin_interactive_session()
         {
-            DExprSeqState::establish_interactive(psm_.expr_alloc(), &psm_);
+            DExprSeqState::establish_interactive(psm_.parser_alloc(), &psm_);
 
         }
 
         void
         SchematikaParser::begin_batch_session()
         {
-            DExprSeqState::establish_batch(psm_.expr_alloc(), &psm_);
+            DExprSeqState::establish_batch(psm_.parser_alloc(), &psm_);
         }
 
         const ParserResult &