diff --git a/xo-procedure2/CMakeLists.txt b/xo-procedure2/CMakeLists.txt
new file mode 100644
index 00000000..8d00f310
--- /dev/null
+++ b/xo-procedure2/CMakeLists.txt
@@ -0,0 +1,41 @@
+# xo-procedure2/CMakeLists.txt
+
+cmake_minimum_required(VERSION 3.10)
+
+project(xo_procedure2 VERSION 1.0)
+enable_language(CXX)
+
+include(GNUInstallDirs)
+include(cmake/xo-bootstrap-macros.cmake)
+
+xo_cxx_toplevel_options3()
+
+# ----------------------------------------------------------------
+# c++ settings
+
+# one-time project-specific c++ flags. usually empty
+set(PROJECT_CXX_FLAGS "")
+add_definitions(${PROJECT_CXX_FLAGS})
+
+# ----------------------------------------------------------------
+# output targets
+
+# note: manual target; generated code committed to git
+xo_add_genfacet(
+    TARGET xo-procedure2-facet-procedure
+    FACET Procedure
+    INPUT idl/Procedure.json5
+    OUTPUT_HPP_DIR include/xo/procedure2
+    OUTPUT_IMPL_SUBDIR detail
+    OUTPUT_CPP_DIR src/procedure2
+    )
+
+add_subdirectory(src/procedure2)
+#add_subdirectory(utest)
+
+# ----------------------------------------------------------------
+# cmake export
+
+#xo_export_cmake_config(${PROJECT_NAME} ${PROJECT_VERSION} ${PROJECT_NAME}Targets)
+
+# end CMakeLists.txt
diff --git a/xo-procedure2/cmake/xo-bootstrap-macros.cmake b/xo-procedure2/cmake/xo-bootstrap-macros.cmake
new file mode 100644
index 00000000..592272c0
--- /dev/null
+++ b/xo-procedure2/cmake/xo-bootstrap-macros.cmake
@@ -0,0 +1,41 @@
+# ----------------------------------------------------------------
+# for example:
+#   $ PREFIX=/usr/local   # for example
+#   $ cmake -DCMAKE_MODULE_PATH=prefix -DCMAKE_INSTALL_PREFIX=$PREFIX -B .build
+#
+# will get
+#   CMAKE_MODULE_PATH
+# from xo-cmake-config --cmake-module-path
+#
+# and expect .cmake macros in
+#   CMAKE_MODULE_PATH/xo_macros/xo_cxx.cmake
+# ----------------------------------------------------------------
+
+find_program(XO_CMAKE_CONFIG_EXECUTABLE NAMES xo-cmake-config REQUIRED)
+
+if ("${XO_CMAKE_CONFIG_EXECUTABLE}" STREQUAL "XO_CMAKE_CONFIG_EXECUTABLE-NOT_FOUND")
+    message(FATAL "could not find xo-cmake-config executable")
+endif()
+
+message(STATUS "XO_CMAKE_CONFIG_EXECUTABLE=${XO_CMAKE_CONFIG_EXECUTABLE}")
+
+if (XO_SUBMODULE_BUILD)
+    if (("${CMAKE_MODULE_PATH}" STREQUAL "") OR ("${CMAKE_MODULE_PATH}" STREQUAL prefix))
+        # local version of xo-cmake macros
+        set(CMAKE_MODULE_PATH "${PROJECT_SOURCE_DIR}/xo-cmake/cmake")
+        message(STATUS "CMAKE_MODULE_PATH=${CMAKE_MODULE_PATH}")
+    endif()
+else()
+    if (("${CMAKE_MODULE_PATH}" STREQUAL "") OR ("${CMAKE_MODULE_PATH}" STREQUAL prefix))
+        # default to typical install location for xo-project-macros
+        execute_process(COMMAND ${XO_CMAKE_CONFIG_EXECUTABLE} --cmake-module-path OUTPUT_VARIABLE CMAKE_MODULE_PATH)
+        message(STATUS "CMAKE_MODULE_PATH=${CMAKE_MODULE_PATH}")
+    endif()
+endif()
+
+# needs to have been installed somewhere on CMAKE_MODULE_PATH,
+# (e.g. from xo-cmake with the same value for CMAKE_INSTALL_PREFIX)
+#
+include(xo_macros/xo_cxx)
+
+xo_cxx_bootstrap_message()
diff --git a/xo-procedure2/cmake/xo_procedure2Config.cmake.in b/xo-procedure2/cmake/xo_procedure2Config.cmake.in
new file mode 100644
index 00000000..0229c033
--- /dev/null
+++ b/xo-procedure2/cmake/xo_procedure2Config.cmake.in
@@ -0,0 +1,13 @@
+@PACKAGE_INIT@
+
+include(CMakeFindDependencyMacro)
+
+# note: changes to find_dependency() calls here
+#       must coordinate with xo_dependency() calls
+#       in CMakeLists.txt
+#
+find_dependency(xo_gc)
+find_dependency(subsys)
+
+include("${CMAKE_CURRENT_LIST_DIR}/@PROJECT_NAME@Targets.cmake")
+check_required_components("@PROJECT_NAME@")
diff --git a/xo-procedure2/idl/Procedure.json5 b/xo-procedure2/idl/Procedure.json5
new file mode 100644
index 00000000..fb43f310
--- /dev/null
+++ b/xo-procedure2/idl/Procedure.json5
@@ -0,0 +1,58 @@
+{
+    mode: "facet",
+    // includes in ASyntaxStateMachine.hpp
+    includes: [
+    ],
+    // extra includes in SyntaxStateMachine.hpp, if any
+    user_hpp_includes: [
+    ],
+    namespace1: "xo",
+    namespace2: "scm",
+    // text after includes, before ASyntaxStateMachine
+    pretext: [ "// {pretex} here" ],
+    facet: "Procedure",
+    detail_subdir: "detail",
+    brief: "abstraction for a schematika procedure i.e. something callable",
+    using_doxygen: true,
+    doc: [
+        "Abstraction for a schematika procedure"
+    ],
+    types: [
+        { name: "AGCObject",
+          definition: "xo::mm::AGCObject",
+          doc: [ "a gc-aware object" ],
+        },
+        // { name: string, doc: [ string ], definition: string },
+    ],
+    const_methods: [
+        {
+            name: "is_nary",
+            doc: [ "true iff procedure takes n arguments" ],
+            return_type: "bool",
+            args: [],
+            const: true,
+            noexcept: true,
+            attributes: []
+        },
+        {
+            name: "n_args",
+            doc: ["number of arguments. -1 for n-ary" ],
+            return_type: "std::int32_t",
+            args: [],
+            const: true,
+            noexcept: true,
+            attributes: []
+        }
+    ],
+    nonconst_methods: [
+        {
+            name: "apply_nocheck",
+            doc: ["invoke procedure; assume arguments satisfy type system" ],
+            return_type: "obj<AGCObject>",
+            args: [
+                {type: "obj<AAllocator>", name: "mm"},
+                {type: "const DArray *", name: "args"},
+            ]
+        }
+    ],
+}
diff --git a/xo-procedure2/include/xo/procedure2/.gitkeep b/xo-procedure2/include/xo/procedure2/.gitkeep
new file mode 100644
index 00000000..e69de29b
diff --git a/xo-procedure2/include/xo/procedure2/DPrimitive.hpp b/xo-procedure2/include/xo/procedure2/DPrimitive.hpp
new file mode 100644
index 00000000..5e5f996c
--- /dev/null
+++ b/xo-procedure2/include/xo/procedure2/DPrimitive.hpp
@@ -0,0 +1,94 @@
+/** @file DPrimitive.hpp
+ *
+ *  @author Roland Conybeare, Jan 2025
+ **/
+
+#pragma once
+
+#include <xo/object2/DArray.hpp>
+#include <xo/gc/GCObjectConversion.hpp>
+#include <xo/gc/GCObject.hpp>
+#include <xo/alloc2/Allocator.hpp>
+
+#include <tuple>
+#include <type_traits>
+#include <utility>
+#include <string_view>
+
+namespace xo {
+    namespace scm {
+        /** @brief Extract return type and argument types from a function type.
+         *
+         *  Primary template (undefined) - specializations handle specific cases
+         **/
+        template <typename Fn>
+        struct FnTraits;
+
+        /** specialization for function pointers **/
+        template <typename R, typename... Args>
+        struct FnTraits<R(*)(Args...)> {
+            /** function return type **/
+            using return_type = R;
+            /** tuple type for function arguments **/
+            using args_tuple = std::tuple<Args...>;
+            /** number of arguments **/
+            static constexpr std::size_t n_args = sizeof...(Args);
+
+            /** arg_type<i> is the type of the i'th argument to Fn **/
+            template <std::size_t I>
+            using arg_type = std::tuple_element_t<I, args_tuple>;
+        };
+
+        /** specialization for function references **/
+        template <typename R, typename... Args>
+        struct FnTraits<R(&)(Args...)> : FnTraits<R(*)(Args...)> {};
+
+        /** specialization for plain function types **/
+        template <typename R, typename... Args>
+        struct FnTraits<R(Args...)> : FnTraits<R(*)(Args...)> {};
+
+        template <typename Fn>
+        class Primitive {
+        public:
+            using AAllocator = xo::mm::AAllocator;
+            using AGCObject = xo::mm::AGCObject;
+            using DArray = xo::scm::DArray;
+            using Traits = FnTraits<Fn>;
+
+        public:
+            Primitive(std::string_view name, Fn fn) : name_{name}, fn_{fn} {}
+
+            bool is_nary() const noexcept { return false; }
+            static constexpr std::int32_t n_args() noexcept { return Traits::n_args; }
+
+            obj<AGCObject> apply_nocheck(obj<AAllocator> mm, const DArray * args) {
+                return _apply_nocheck(mm, args,
+                                  std::make_index_sequence<Traits::n_args>{});
+            }
+
+        private:
+            template <std::size_t... Is>
+            obj<AGCObject> _apply_nocheck(obj<AAllocator> mm,
+                                          const DArray * args,
+                                          std::index_sequence<Is...>)
+            {
+                using R = typename Traits::return_type;
+
+                R result
+                    = fn_(GCObjectConversion<typename Traits::template arg_type<Is>>::from_gco(mm, args->at(Is))...
+                );
+
+                return GCObjectConversion<R>::to_gco(mm, result);
+            }
+
+        private:
+            /** name of this primitive **/
+            std::string_view name_;
+            /** function implementation **/
+            Fn fn_;
+        }; /*Primitive*/
+
+    } /*namespace scm*/
+} /*namespace xo*/
+
+/* end DPrimitive.hpp */
diff --git a/xo-procedure2/include/xo/procedure2/Procedure.hpp b/xo-procedure2/include/xo/procedure2/Procedure.hpp
new file mode 100644
index 00000000..8b2cd91a
--- /dev/null
+++ b/xo-procedure2/include/xo/procedure2/Procedure.hpp
@@ -0,0 +1,22 @@
+/** @file Procedure.hpp
+ *
+ *  Generated automagically from ingredients:
+ *  1. code generator:
+ *       [/Users/roland/proj/xo-umbrella2/xo-facet/codegen/genfacet]
+ *     arguments:
+ *       --input [idl/Procedure.json5]
+ *  2. jinja2 template for facet .hpp file:
+ *       [facet.hpp.j2]
+ *  3. idl for facet methods
+ *       [idl/Procedure.json5]
+ **/
+
+#pragma once
+
+#include "detail/AProcedure.hpp"
+#include "detail/IProcedure_Any.hpp"
+#include "detail/IProcedure_Xfer.hpp"
+#include "detail/RProcedure.hpp"
+
+
+/* end Procedure.hpp */
\ No newline at end of file
diff --git a/xo-procedure2/include/xo/procedure2/detail/AProcedure.hpp b/xo-procedure2/include/xo/procedure2/detail/AProcedure.hpp
new file mode 100644
index 00000000..c0b22f49
--- /dev/null
+++ b/xo-procedure2/include/xo/procedure2/detail/AProcedure.hpp
@@ -0,0 +1,77 @@
+/** @file AProcedure.hpp
+ *
+ *  Generated automagically from ingredients:
+ *  1. code generator:
+ *       [/Users/roland/proj/xo-umbrella2/xo-facet/codegen/genfacet]
+ *     arguments:
+ *       --input [idl/Procedure.json5]
+ *  2. jinja2 template for abstract facet .hpp file:
+ *       [abstract_facet.hpp.j2]
+ *  3. idl for facet methods
+ *       [idl/Procedure.json5]
+ **/
+
+#pragma once
+
+// includes (via {facet_includes})
+#include <xo/facet/obj.hpp>
+#include <xo/facet/facet_implementation.hpp>
+#include <xo/facet/typeseq.hpp>
+
+// {pretex} here
+
+namespace xo {
+namespace scm {
+
+using Copaque = const void *;
+using Opaque = void *;
+
+/**
+Abstraction for a schematika procedure
+**/
+class AProcedure {
+public:
+    /** @defgroup scm-procedure-type-traits **/
+    ///@{
+    // types
+    /** integer identifying a type **/
+    using typeseq = xo::facet::typeseq;
+    using Copaque = const void *;
+    using Opaque = void *;
+    /** a gc-aware object **/
+    using AGCObject = xo::mm::AGCObject;
+    ///@}
+
+    /** @defgroup scm-procedure-methods **/
+    ///@{
+    // const methods
+    /** RTTI: unique id# for actual runtime data representation **/
+    virtual typeseq _typeseq() const noexcept = 0;
+    /** true iff procedure takes n arguments **/
+    virtual bool is_nary(Copaque data)  const  noexcept = 0;
+    /** number of arguments. -1 for n-ary **/
+    virtual std::int32_t n_args(Copaque data)  const  noexcept = 0;
+
+    // nonconst methods
+    /** invoke procedure; assume arguments satisfy type system **/
+    virtual obj<AGCObject> apply_nocheck(Opaque data, obj<AAllocator> mm, const DArray * args)  = 0;
+    ///@}
+}; /*AProcedure*/
+
+/** Implementation IProcedure_DRepr of AProcedure for state DRepr
+ *  should provide a specialization:
+ *
+ *    template <>
+ *    struct xo::facet::FacetImplementation<AProcedure, DRepr> {
+ *        using Impltype = IProcedure_DRepr;
+ *    };
+ *
+ *  then IProcedure_ImplType<DRepr> --> IProcedure_DRepr
+ **/
+template <typename DRepr>
+using IProcedure_ImplType = xo::facet::FacetImplType<AProcedure, DRepr>;
+
+} /*namespace scm*/
+} /*namespace xo*/
+
+/* AProcedure.hpp */
\ No newline at end of file
diff --git a/xo-procedure2/include/xo/procedure2/detail/IProcedure_Any.hpp b/xo-procedure2/include/xo/procedure2/detail/IProcedure_Any.hpp
new file mode 100644
index 00000000..c1b8c9d6
--- /dev/null
+++ b/xo-procedure2/include/xo/procedure2/detail/IProcedure_Any.hpp
@@ -0,0 +1,88 @@
+/** @file IProcedure_Any.hpp
+ *
+ *  Generated automagically from ingredients:
+ *  1. code generator:
+ *       [/Users/roland/proj/xo-umbrella2/xo-facet/codegen/genfacet]
+ *     arguments:
+ *       --input [idl/Procedure.json5]
+ *  2. jinja2 template for abstract facet .hpp file:
+ *       [iface_facet_any.hpp.j2]
+ *  3. idl for facet methods
+ *       [idl/Procedure.json5]
+ **/
+
+#pragma once
+
+#include "AProcedure.hpp"
+#include <xo/facet/obj.hpp>
+
+namespace xo { namespace scm { class IProcedure_Any; } }
+
+namespace xo {
+namespace facet {
+
+template <>
+struct FacetImplementation<xo::scm::AProcedure,
+                           DVariantPlaceholder>
+{
+    using ImplType = xo::scm::IProcedure_Any;
+};
+
+}
+}
+
+namespace xo {
+namespace scm {
+
+    /** @class IProcedure_Any
+     *  @brief AProcedure implementation for empty variant instance
+     **/
+    class IProcedure_Any : public AProcedure {
+    public:
+        /** @defgroup scm-procedure-any-type-traits **/
+        ///@{
+
+        /** integer identifying a type **/
+        using typeseq = xo::facet::typeseq;
+        using AGCObject = AProcedure::AGCObject;
+
+        ///@}
+        /** @defgroup scm-procedure-any-methods **/
+        ///@{
+
+        const AProcedure * iface() const { return std::launder(this); }
+
+        // from AProcedure
+
+        // const methods
+        typeseq _typeseq() const noexcept override { return s_typeseq; }
+        [[noreturn]] bool is_nary(Copaque)  const  noexcept override { _fatal(); }
+        [[noreturn]] std::int32_t n_args(Copaque)  const  noexcept override { _fatal(); }
+
+        // nonconst methods
+        [[noreturn]] obj<AGCObject> apply_nocheck(Opaque, obj<AAllocator>, const DArray *)  override;
+
+        ///@}
+
+    private:
+        /** @defgraoup scm-procedure-any-private-methods **/
+        ///@{
+
+        [[noreturn]] static void _fatal();
+
+        ///@}
+
+    public:
+        /** @defgroup scm-procedure-any-member-vars **/
+        ///@{
+
+        static typeseq s_typeseq;
+        static bool _valid;
+
+        ///@}
+    };
+
+} /*namespace scm */
+} /*namespace xo */
+
+/* IProcedure_Any.hpp */
\ No newline at end of file
diff --git a/xo-procedure2/include/xo/procedure2/detail/IProcedure_Xfer.hpp b/xo-procedure2/include/xo/procedure2/detail/IProcedure_Xfer.hpp
new file mode 100644
index 00000000..dfe8a558
--- /dev/null
+++ b/xo-procedure2/include/xo/procedure2/detail/IProcedure_Xfer.hpp
@@ -0,0 +1,86 @@
+/** @file IProcedure_Xfer.hpp
+ *
+ *  Generated automagically from ingredients:
+ *  1. code generator:
+ *       [/Users/roland/proj/xo-umbrella2/xo-facet/codegen/genfacet]
+ *     arguments:
+ *       --input [idl/Procedure.json5]
+ *  2. jinja2 template for abstract facet .hpp file:
+ *       [iface_facet_any.hpp.j2]
+ *  3. idl for facet methods
+ *       [idl/Procedure.json5]
+ **/
+
+#pragma once
+
+
+namespace xo {
+namespace scm {
+    /** @class IProcedure_Xfer
+     **/
+    template <typename DRepr, typename IProcedure_DRepr>
+    class IProcedure_Xfer : public AProcedure {
+    public:
+        /** @defgroup scm-procedure-xfer-type-traits **/
+        ///@{
+        /** actual implementation (not generated; often delegates to DRepr) **/
+        using Impl = IProcedure_DRepr;
+        /** integer identifying a type **/
+        using typeseq = AProcedure::typeseq;
+        using AGCObject = AProcedure::AGCObject;
+        ///@}
+
+        /** @defgroup scm-procedure-xfer-methods **/
+        ///@{
+
+        static const DRepr & _dcast(Copaque d) { return *(const DRepr *)d; }
+        static DRepr & _dcast(Opaque d) { return *(DRepr *)d; }
+
+        // from AProcedure
+
+        // const methods
+        typeseq _typeseq() const noexcept override { return s_typeseq; }
+        bool is_nary(Copaque data)  const  noexcept override {
+            return I::is_nary(_dcast(data));
+        }
+        std::int32_t n_args(Copaque data)  const  noexcept override {
+            return I::n_args(_dcast(data));
+        }
+
+        // non-const methods
+        obj<AGCObject> apply_nocheck(Opaque data, obj<AAllocator> mm, const DArray * args)  override {
+            return I::apply_nocheck(_dcast(data), mm, args);
+        }
+
+        ///@}
+
+    private:
+        using I = Impl;
+
+    public:
+        /** @defgroup scm-procedure-xfer-member-vars **/
+        ///@{
+
+        /** typeseq for template parameter DRepr **/
+        static typeseq s_typeseq;
+        /** true iff satisfies facet implementation **/
+        static bool _valid;
+
+        ///@}
+    };
+
+    template <typename DRepr, typename IProcedure_DRepr>
+    xo::facet::typeseq
+    IProcedure_Xfer<DRepr, IProcedure_DRepr>::s_typeseq
+      = xo::facet::typeseq::id<DRepr>();
+
+    template <typename DRepr, typename IProcedure_DRepr>
+    bool
+    IProcedure_Xfer<DRepr, IProcedure_DRepr>::_valid
+      = xo::facet::valid_facet_implementation<AProcedure,
+                                              IProcedure_Xfer>();
+
+} /*namespace scm */
+} /*namespace xo*/
+
+/* end IProcedure_Xfer.hpp */
\ No newline at end of file
diff --git a/xo-procedure2/include/xo/procedure2/detail/RProcedure.hpp b/xo-procedure2/include/xo/procedure2/detail/RProcedure.hpp
new file mode 100644
index 00000000..dc0f30d8
--- /dev/null
+++ b/xo-procedure2/include/xo/procedure2/detail/RProcedure.hpp
@@ -0,0 +1,86 @@
+/** @file RProcedure.hpp
+ *
+ *  Generated automagically from ingredients:
+ *  1. code generator:
+ *       [/Users/roland/proj/xo-umbrella2/xo-facet/codegen/genfacet]
+ *     arguments:
+ *       --input [idl/Procedure.json5]
+ *  2. jinja2 template for abstract facet .hpp file:
+ *       [iface_facet_any.hpp.j2]
+ *  3. idl for facet methods
+ *       [idl/Procedure.json5]
+ **/
+
+#pragma once
+
+#include "AProcedure.hpp"
+
+namespace xo {
+namespace scm {
+
+/** @class RProcedure
+ **/
+template <typename Object>
+class RProcedure : public Object {
+private:
+    using O = Object;
+
+public:
+    /** @defgroup scm-procedure-router-type-traits **/
+    ///@{
+    using ObjectType = Object;
+    using DataPtr = Object::DataPtr;
+    using typeseq = xo::reflect::typeseq;
+    using AGCObject = AProcedure::AGCObject;
+    ///@}
+
+    /** @defgroup scm-procedure-router-ctors **/
+    ///@{
+    RProcedure() {}
+    RProcedure(Object::DataPtr data) : Object{std::move(data)} {}
+    RProcedure(const AProcedure * iface, void * data)
+      requires std::is_same_v<typename Object::DataType, xo::facet::DVariantPlaceholder>
+      : Object(iface, data) {}
+
+    ///@}
+    /** @defgroup scm-procedure-router-methods **/
+    ///@{
+
+    // const methods
+    typeseq _typeseq() const noexcept { return O::iface()->_typeseq(); }
+    bool is_nary()  const  noexcept {
+        return O::iface()->is_nary(O::data());
+    }
+    std::int32_t n_args()  const  noexcept {
+        return O::iface()->n_args(O::data());
+    }
+
+    // non-const methods (still const in router!)
+    obj<AGCObject> apply_nocheck(obj<AAllocator> mm, const DArray * args)  {
+        return O::iface()->apply_nocheck(O::data(), mm, args);
+    }
+
+    ///@}
+    /** @defgroup scm-procedure-member-vars **/
+    ///@{
+
+    static bool _valid;
+
+    ///@}
+};
+
+template <typename Object>
+bool
+RProcedure<Object>::_valid = xo::facet::valid_object_router<Object>();
+
+} /*namespace scm*/
+} /*namespace xo*/
+
+namespace xo { namespace facet {
+    template <typename Object>
+    struct RoutingFor<xo::scm::AProcedure, Object> {
+        using RoutingType = xo::scm::RProcedure<Object>;
+    };
+} }
+
+/* end RProcedure.hpp */
\ No newline at end of file
diff --git a/xo-procedure2/include/xo/procedure2/init_primitives.hpp b/xo-procedure2/include/xo/procedure2/init_primitives.hpp
new file mode 100644
index 00000000..d4150d2d
--- /dev/null
+++ b/xo-procedure2/include/xo/procedure2/init_primitives.hpp
@@ -0,0 +1,29 @@
+/** @file init_primitives.hpp **/
+
+#pragma once
+
+#include "DPrimitive.hpp"
+
+namespace xo {
+    namespace scm {
+        using Primitive_f64_1_f64 = Primitive<double (*)(double)>;
+        using Primitive_f64_2_f64_f64 = Primitive<double (*)(double, double)>;
+
+        struct Primitives {
+            static Primitive_f64_1_f64 s_neg_f64_pm;
+
+            static Primitive_f64_2_f64_f64 s_add_f64_f64_pm;
+            static Primitive_f64_2_f64_f64 s_sub_f64_f64_pm;
+            static Primitive_f64_2_f64_f64 s_mul_f64_f64_pm;
+            static Primitive_f64_2_f64_f64 s_div_f64_f64_pm;
+            static Primitive_f64_2_f64_f64 s_pow_f64_f64_pm;
+
+            static Primitive_f64_1_f64 s_log_f64_pm;
+            static Primitive_f64_1_f64 s_sin_f64_pm;
+            static Primitive_f64_1_f64 s_cos_f64_pm;
+            static Primitive_f64_1_f64 s_tan_f64_pm;
+        };
+    }
+}
+
+/* end init_primitives.hpp */
diff --git a/xo-procedure2/include/xo/procedure2/init_procedure2.hpp b/xo-procedure2/include/xo/procedure2/init_procedure2.hpp
new file mode 100644
index 00000000..793cc061
--- /dev/null
+++ b/xo-procedure2/include/xo/procedure2/init_procedure2.hpp
@@ -0,0 +1,21 @@
+/** @file init_procedure2.hpp
+ *
+ *  @author Roland Conybeare, Jan 2026
+ **/
+
+#pragma once
+
+#include <xo/subsys/Subsystem.hpp>
+
+namespace xo {
+    /* tag to represent the xo-procedure2/ subsystem within ordered iniitalization */
+    enum S_procedure2_tag {};
+
+    template <>
+    struct InitSubsys<S_procedure2_tag> {
+        static void init();
+        static InitEvidence require();
+    };
+} /*namespace xo*/
+
+/* end init_procedure2.hpp */
diff --git a/xo-procedure2/include/xo/procedure2/primitives.hpp b/xo-procedure2/include/xo/procedure2/primitives.hpp
new file mode 100644
index 00000000..e2e0d88a
--- /dev/null
+++ b/xo-procedure2/include/xo/procedure2/primitives.hpp
@@ -0,0 +1,13 @@
+/** @file primitives.hpp **/
+
+#pragma once
+
+namespace xo {
+    namespace scm {
+        struct Primitives {
+            static void init_primitives();
+        };
+    }
+}
+
+/* end primitives.hpp */
diff --git a/xo-procedure2/src/procedure2/CMakeLists.txt b/xo-procedure2/src/procedure2/CMakeLists.txt
new file mode 100644
index 00000000..edc5d3ce
--- /dev/null
+++ b/xo-procedure2/src/procedure2/CMakeLists.txt
@@ -0,0 +1,26 @@
+# xo-procedure2/src/CMakeLists.txt
+
+set(SELF_LIB xo_procedure2)
+set(SELF_SRCS
+    init_procedure2.cpp
+    init_primitives.cpp
+    DPrimitive.cpp
+    # Add source files here, e.g.:
+    # procedure2.cpp
+)
+
+xo_add_shared_library4(${SELF_LIB} ${PROJECT_NAME}Targets ${PROJECT_VERSION} 1 ${SELF_SRCS})
+xo_install_include_tree3(include/xo/procedure2)
+
+# ----------------------------------------------------------------
+# input dependencies
+#
+# NOTE: dependency set here must be kept consistent with
+#       xo-procedure2/cmake/xo_procedure2Config.cmake.in
+
+xo_dependency(${SELF_LIB} xo_object2)
+xo_dependency(${SELF_LIB} xo_gc)
+xo_dependency(${SELF_LIB} subsys)
+#xo_dependency(${SELF_LIB} xo_indentlog)
+
+# end src/CMakeLists.txt
diff --git a/xo-procedure2/src/procedure2/DPrimitive.cpp b/xo-procedure2/src/procedure2/DPrimitive.cpp
new file mode 100644
index 00000000..ab335d8d
--- /dev/null
+++ b/xo-procedure2/src/procedure2/DPrimitive.cpp
@@ -0,0 +1,16 @@
+/** @file DPrimitive.cpp
+ *
+ *  @author Roland Conybeare, Jan 2026
+ **/
+
+#include "DPrimitive.hpp"
+#include <xo/gc/GCObject.hpp>
+
+namespace xo {
+    namespace scm {
+
+
+    } /*namespace scm*/
+} /*namespace xo*/
+
+/* end DPrimitive.cpp */
diff --git a/xo-procedure2/src/procedure2/IProcedure_Any.cpp b/xo-procedure2/src/procedure2/IProcedure_Any.cpp
new file mode 100644
index 00000000..3044c104
--- /dev/null
+++ b/xo-procedure2/src/procedure2/IProcedure_Any.cpp
@@ -0,0 +1,47 @@
+/** @file IProcedure_Any.cpp
+ *
+ **/
+
+#include "detail/IProcedure_Any.hpp"
+#include <iostream>
+
+namespace xo {
+namespace scm {
+
+using xo::facet::DVariantPlaceholder;
+using xo::facet::typeseq;
+using xo::facet::valid_facet_implementation;
+
+void
+IProcedure_Any::_fatal()
+{
+    /* control here on uninitialized IAllocator_Any.
+     * Initialized instance will have specific implementation type
+     */
+    std::cerr << "fatal"
+              << ": attempt to call uninitialized"
+              << " IProcedure_Any method"
+              << std::endl;
+    std::terminate();
+}
+
+typeseq
+IProcedure_Any::s_typeseq = typeseq::id<DVariantPlaceholder>();
+
+bool
+IProcedure_Any::_valid
+  = valid_facet_implementation<AProcedure, IProcedure_Any>();
+
+// nonconst methods
+
+auto
+IProcedure_Any::apply_nocheck(Opaque, obj<AAllocator>, const DArray *)  -> obj<AGCObject>
+{
+    _fatal();
+}
+
+
+} /*namespace scm*/
+} /*namespace xo*/
+
+/* end IProcedure_Any.cpp */
\ No newline at end of file
diff --git a/xo-procedure2/src/procedure2/init_primitives.cpp b/xo-procedure2/src/procedure2/init_primitives.cpp
new file mode 100644
index 00000000..169b660e
--- /dev/null
+++ b/xo-procedure2/src/procedure2/init_primitives.cpp
@@ -0,0 +1,95 @@
+/** @file init_primitives.cpp
+ *
+ *  @author Roland Conybeare, Jan 2026
+ **/
+
+#include "init_primitives.hpp"
+#include "DPrimitive.hpp"
+
+namespace xo {
+    namespace scm {
+        double
+        neg_f64(double x) {
+            return -x;
+        }
+
+        double
+        add_f64_f64(double x, double y) {
+            return x + y;
+        }
+
+        double
+        sub_f64_f64(double x, double y) {
+            return x - y;
+        }
+
+        double
+        mul_f64_f64(double x, double y) {
+            return x * y;
+        }
+
+        double
+        div_f64_f64(double x, double y) {
+            return x / y;
+        }
+
+        double
+        pow_f64_f64(double x, double y) {
+            return ::pow(x, y);
+        }
+
+        double
+        log_f64(double x) {
+            return ::log(x);
+        }
+
+        double
+        sin_f64(double x) {
+            return ::sin(x);
+        }
+
+        double
+        cos_f64(double x) {
+            return ::cos(x);
+        }
+
+        double
+        tan_f64(double x) {
+            return ::tan(x);
+        }
+
+        Primitive_f64_1_f64
+        Primitives::s_neg_f64_pm("_neg_d",
+                                 &neg_f64);
+
+        Primitive_f64_2_f64_f64
+        Primitives::s_add_f64_f64_pm("_add_d_d", &add_f64_f64);
+
+        Primitive_f64_2_f64_f64
+        Primitives::s_sub_f64_f64_pm("_sub_d_d", &sub_f64_f64);
+
+        Primitive_f64_2_f64_f64
+        Primitives::s_mul_f64_f64_pm("_mul_d_d", &mul_f64_f64);
+
+        Primitive_f64_2_f64_f64
+        Primitives::s_div_f64_f64_pm("_div_d_d", &div_f64_f64);
+
+        Primitive_f64_2_f64_f64
+        Primitives::s_pow_f64_f64_pm("_pow_d_d", &pow_f64_f64);
+
+        Primitive_f64_1_f64
+        Primitives::s_log_f64_pm("_log_d", &log_f64);
+
+        Primitive_f64_1_f64
+        Primitives::s_sin_f64_pm("_sin_d", &sin_f64);
+
+        Primitive_f64_1_f64
+        Primitives::s_cos_f64_pm("_cos_d", &cos_f64);
+
+        Primitive_f64_1_f64
+        Primitives::s_tan_f64_pm("_tan_d", &tan_f64);
+
+    } /*namespace scm*/
+} /*namespace xo*/
+
+/* end init_primitives.cpp */
diff --git a/xo-procedure2/src/procedure2/init_procedure2.cpp b/xo-procedure2/src/procedure2/init_procedure2.cpp
new file mode 100644
index 00000000..fc316653
--- /dev/null
+++ b/xo-procedure2/src/procedure2/init_procedure2.cpp
@@ -0,0 +1,32 @@
+/** @file init_procedure2.cpp
+ *
+ *  @author Roland Conybeare, Jan 2026
+**/
+
+#include "init_procedure2.hpp"
+#include "init_primitives.hpp"
+//#include "procedure2_register_facets.hpp"
+//#include "procedure2_register_types.hpp"
+#include <xo/gc/CollectorTypeRegistry.hpp>
+
+namespace xo {
+    using xo::scm::Primitives;
+
+    void
+    InitSubsys<S_procedure2_tag>::init()
+    {
+    }
+
+    InitEvidence
+    InitSubsys<S_procedure2_tag>::require()
+    {
+        InitEvidence retval;
+
+        /* xo-procedure2/'s own initialization code */
+        retval ^= Subsystem::provide<S_procedure2_tag>("procedure2", &init);
+
+        return retval;
+    }
+} /*namespace xo*/
+
+/* end init_procedure2.cpp */