diff --git a/lib/exec.c b/lib/exec.c
index 856c5e0..526548d 100644
--- a/lib/exec.c
+++ b/lib/exec.c
@@ -3887,7 +3887,7 @@ if (do_throw(hcl, hcl->_nil, fetched_instruction_pointer) <= -1)
 			case HCL_CODE_CLASS_IMSTORE:
 			{
 				hcl_oop_t class_;
-				hcl_oop_t mdic, cons, blk;
+				hcl_oop_t mdic, cons, blk, car, cdr, name;
 
 				FETCH_PARAM_CODE_TO (hcl, b1);
 				LOG_INST_2 (hcl, "class_%hsmstore %zu", (bcode == HCL_CODE_CLASS_CMSTORE? "c": (bcode == HCL_CODE_CLASS_CIMSTORE? "ci": "i")), b1);
@@ -3912,11 +3912,17 @@ if (do_throw(hcl, hcl->_nil, fetched_instruction_pointer) <= -1)
 
 				blk = HCL_STACK_GETTOP(hcl);
 				hcl_pushvolat (hcl, (hcl_oop_t*)&mdic);
-				cons = hcl_makecons(hcl, (bcode == HCL_CODE_CLASS_IMSTORE? hcl->_nil: blk), (bcode == HCL_CODE_CLASS_CMSTORE? hcl->_nil: blk));
+				/* let car point to the instance method,
+				 * let cdr point to the class method */
+				car = (bcode == HCL_CODE_CLASS_IMSTORE? hcl->_nil: blk);
+				cdr = (bcode == HCL_CODE_CLASS_CMSTORE? hcl->_nil: blk);
+				cons = hcl_makecons(hcl, car, cdr);
 				hcl_popvolat (hcl);
 				if (HCL_UNLIKELY(!cons)) goto oops_with_errmsg_supplement;
 
-				if (!hcl_putatdic(hcl, (hcl_oop_dic_t)mdic, hcl->active_function->literal_frame[b1], cons)) goto oops_with_errmsg_supplement;
+				/* put the code at method dictionary */
+				name = hcl->active_function->literal_frame[b1]; /* method name */
+				if (!hcl_putatdic(hcl, (hcl_oop_dic_t)mdic, name, cons)) goto oops_with_errmsg_supplement;
 				break;
 			}
 			/* -------------------------------------------------------- */
diff --git a/lib/gc.c b/lib/gc.c
index 3c1b05b..48f0c9f 100644
--- a/lib/gc.c
+++ b/lib/gc.c
@@ -66,6 +66,435 @@ static struct
 /* ========================================================================= */
 
 
+
+static struct
+{
+	const char* name;
+	hcl_oow_t c_offset; /* class offset */
+	hcl_oow_t sc_offset; /* superclass offset */
+	hcl_oow_t nivars;
+	hcl_oow_t ncvars;
+} kctab[] = {
+	{ "Apex",
+	  HCL_OFFSETOF(hcl_t, c_apex),
+	  HCL_TYPE_MAX(hcl_oow_t),
+	  0, 0 },
+
+	{ "Object",
+	  HCL_OFFSETOF(hcl_t, c_object),
+	  HCL_OFFSETOF(hcl_t, c_apex),
+	  0, 0 },
+
+	{ "UndefinedObject",
+	  HCL_OFFSETOF(hcl_t, c_undefobj),
+	  HCL_OFFSETOF(hcl_t, c_apex),
+	  0, 0 },
+
+	{ "Class",
+	  HCL_OFFSETOF(hcl_t, c_class),
+	  HCL_OFFSETOF(hcl_t, c_object),
+	  HCL_CLASS_NAMED_INSTVARS, 0 },
+
+	{ "String",
+	  HCL_OFFSETOF(hcl_t, c_string),
+	  HCL_OFFSETOF(hcl_t, c_object),
+	  0, 0 },
+
+	{ "Symbol",
+	  HCL_OFFSETOF(hcl_t, c_symbol),
+	  HCL_OFFSETOF(hcl_t, c_string),
+	  0, 0 },
+
+#if 0
+	{ "Boolean",
+	  HCL_OFFSETOF(hcl_t, c_boolean),
+	  HCL_OFFSETOF(hcl_t, c_object),
+	  0, 0 },
+
+	{ "True",
+	  HCL_OFFSETOF(hcl_t, c_true),
+	  HCL_OFFSETOF(hcl_t, c_boolean),
+	  0, 0 },
+
+	{ "False",
+	  HCL_OFFSETOF(hcl_t, c_false),
+	  HCL_OFFSETOF(hcl_t, c_boolean),
+	  0, 0 },
+#endif
+
+	{ "System",
+	  HCL_OFFSETOF(hcl_t, c_system),
+	  HCL_OFFSETOF(hcl_t, c_object),
+	  0, 0 },
+};
+
+/* ========================================================================= */
+
+/*
+ *    Apex......................
+ *    ^ ^ ^                    :   .......
+ *    | | |                    v   v     :
+ *    | | +------------------- Class .....
+ *    | |                       ^  ^
+ *    | +-------- NilObject ......:  :
+ *    |                 ^........ nil  :
+ *   Object ...........................:
+ *    ^
+ *    |
+ *
+ * The class hierarchy is roughly as follows:
+ *
+ *   Apex
+ *      Class
+ *      NilObject
+ *      Object
+ *         Collection
+ *            IndexedCollection
+ *               FixedSizedCollection
+ *                  Array
+ *                  ByteArray
+ *                     String
+ *                        Symbol
+ *            Set
+ *               Dictionary
+ *                  SystemDictionary
+ *               SymbolSet
+ *         Magnitude
+ *            Association
+ *            Character
+ *            Number
+ *               Integer
+ *                  SmallInteger
+ *                  LargeInteger
+ *                     LargePositiveInteger
+ *                     LargeNegativeInteger
+ *
+ * Apex has no instance variables.
+ *
+ */
+
+struct kernel_class_info_t
+{
+	const hcl_bch_t* name;
+	int class_flags;
+	int class_num_classvars;
+
+	int class_spec_named_instvars;
+	int class_spec_flags;
+	int class_spec_indexed_type;
+
+	hcl_oow_t  offset;
+};
+typedef struct kernel_class_info_t kernel_class_info_t;
+
+static kernel_class_info_t kernel_classes[] =
+{
+	/* --------------------------------------------------------------
+	 * Apex            - proto-object with 1 class variable.
+	 * UndefinedObject - class for the nil object.
+	 * Object          - top of all ordinary objects.
+	 * String
+	 * Symbol
+	 * Array
+	 * ByteArray
+	 * SymbolSet
+	 * Character
+	 * SmallIntger
+	 * -------------------------------------------------------------- */
+
+	{ "Apex",
+	  0,
+	  0,
+	  0,
+	  0,
+	  HCL_OBJ_TYPE_OOP,
+	  HCL_OFFSETOF(hcl_t, c_apex) },
+
+	{ "UndefinedObject",
+	  0,
+	  0,
+	  0,
+	  0,
+	  HCL_OBJ_TYPE_OOP,
+	  HCL_OFFSETOF(hcl_t, c_undefobj) },
+
+#define KCI_CLASS 2 /* index to the Class entry in this table */
+	{ "Class",
+	  HCL_CLASS_SELFSPEC_FLAG_LIMITED,
+	  0,
+	  HCL_CLASS_NAMED_INSTVARS,
+	  HCL_CLASS_SPEC_FLAG_INDEXED | HCL_CLASS_SPEC_FLAG_UNCOPYABLE,
+	  HCL_OBJ_TYPE_OOP,
+	  HCL_OFFSETOF(hcl_t, c_class) },
+
+#if 0
+	{ "Interface",
+	  HCL_CLASS_SELFSPEC_FLAG_LIMITED,
+	  0,
+	  HCL_INTERFACE_NAMED_INSTVARS,
+	  HCL_CLASS_SPEC_FLAG_INDEXED | HCL_CLASS_SPEC_FLAG_UNCOPYABLE,
+	  HCL_OBJ_TYPE_OOP,
+	  HCL_OFFSETOF(hcl_t, _interface) },
+#endif
+
+	{ "Object",
+	  0,
+	  0,
+	  0,
+	  0,
+	  HCL_OBJ_TYPE_OOP,
+	  HCL_OFFSETOF(hcl_t, c_object) },
+
+	{ "String",
+	  0,
+	  0,
+	  0,
+	  HCL_CLASS_SPEC_FLAG_INDEXED,
+	  HCL_OBJ_TYPE_CHAR,
+	  HCL_OFFSETOF(hcl_t, c_string) },
+
+	{ "Symbol",
+	  HCL_CLASS_SELFSPEC_FLAG_FINAL | HCL_CLASS_SELFSPEC_FLAG_LIMITED,
+	  0,
+	  0,
+	  HCL_CLASS_SPEC_FLAG_INDEXED | HCL_CLASS_SPEC_FLAG_IMMUTABLE,
+	  HCL_OBJ_TYPE_CHAR,
+	  HCL_OFFSETOF(hcl_t, c_symbol) },
+
+	{ "Array",
+	  0,
+	  0,
+	  0,
+	  HCL_CLASS_SPEC_FLAG_INDEXED,
+	  HCL_OBJ_TYPE_OOP,
+	  HCL_OFFSETOF(hcl_t, c_array) },
+
+	{ "ByteArray",
+	  0,
+	  0,
+	  0,
+	  HCL_CLASS_SPEC_FLAG_INDEXED,
+	  HCL_OBJ_TYPE_BYTE,
+	  HCL_OFFSETOF(hcl_t, c_byte_array) },
+
+	{ "SymbolTable",
+	  0,
+	  0,
+	  HCL_DIC_NAMED_INSTVARS,
+	  0,
+	  HCL_OBJ_TYPE_OOP,
+	  HCL_OFFSETOF(hcl_t, c_symtab) },
+
+	{ "Dictionary",
+	  0,
+	  0,
+	  HCL_DIC_NAMED_INSTVARS,
+	  0,
+	  HCL_OBJ_TYPE_OOP,
+	  HCL_OFFSETOF(hcl_t, c_dictionary) },
+
+	{ "Cons",
+	  0,
+	  0,
+	  HCL_CONS_NAMED_INSTVARS,
+	  0,
+	  HCL_OBJ_TYPE_OOP,
+	  HCL_OFFSETOF(hcl_t, c_cons) },
+
+#if 0
+	{ "Namespace",
+	  HCL_CLASS_SELFSPEC_FLAG_LIMITED,
+	  0,
+	  HCL_NSDIC_NAMED_INSTVARS,
+	  0,
+	  HCL_OBJ_TYPE_OOP,
+	  HCL_OFFSETOF(hcl_t, c_namespace) },
+
+	{ "PoolDictionary",
+	  0,
+	  0,
+	  HCL_DIC_NAMED_INSTVARS,
+	  0,
+	  HCL_OBJ_TYPE_OOP,
+	  HCL_OFFSETOF(hcl_t, c_pool_dictionary) },
+#endif
+
+	{ "MethodDictionary",
+	  0,
+	  0,
+	  HCL_DIC_NAMED_INSTVARS,
+	  0,
+	  HCL_OBJ_TYPE_OOP,
+	  HCL_OFFSETOF(hcl_t, c_method_dictionary) },
+
+#if 0
+	{ "CompiledMethod",
+	  0,
+	  0,
+	  HCL_METHOD_NAMED_INSTVARS,
+	  HCL_CLASS_SPEC_FLAG_INDEXED,
+	  HCL_OBJ_TYPE_OOP,
+	  HCL_OFFSETOF(hcl_t, c_method) },
+
+	{ "MethodSignature",
+	  0,
+	  0,
+	  HCL_METHSIG_NAMED_INSTVARS,
+	  HCL_CLASS_SPEC_FLAG_INDEXED,
+	  HCL_OBJ_TYPE_OOP,
+	  HCL_OFFSETOF(hcl_t, c_methsig) },
+#endif
+
+	{ "CompiledBlock",
+	  0,
+	  0,
+	  HCL_BLOCK_NAMED_INSTVARS,
+	  0,
+	  HCL_OBJ_TYPE_OOP,
+	  HCL_OFFSETOF(hcl_t, c_block) },
+
+	{ "MethodContext",
+	  HCL_CLASS_SELFSPEC_FLAG_FINAL | HCL_CLASS_SELFSPEC_FLAG_LIMITED,
+	  0,
+	  HCL_CONTEXT_NAMED_INSTVARS,
+	  HCL_CLASS_SPEC_FLAG_INDEXED,
+	  HCL_OBJ_TYPE_OOP,
+	  HCL_OFFSETOF(hcl_t, c_method_context) },
+
+	{ "BlockContext",
+	  HCL_CLASS_SELFSPEC_FLAG_FINAL | HCL_CLASS_SELFSPEC_FLAG_LIMITED,
+	  0,
+	  HCL_CONTEXT_NAMED_INSTVARS,
+	  HCL_CLASS_SPEC_FLAG_INDEXED,
+	  HCL_OBJ_TYPE_OOP,
+	  HCL_OFFSETOF(hcl_t, c_block_context) },
+
+	{ "Process",
+	  HCL_CLASS_SELFSPEC_FLAG_FINAL | HCL_CLASS_SELFSPEC_FLAG_LIMITED,
+	  0,
+	  HCL_PROCESS_NAMED_INSTVARS,
+	  HCL_CLASS_SPEC_FLAG_INDEXED | HCL_CLASS_SPEC_FLAG_UNCOPYABLE,
+	  HCL_OBJ_TYPE_OOP,
+	  HCL_OFFSETOF(hcl_t, c_process) },
+
+	{ "Semaphore",
+	  0,
+	  0,
+	  HCL_SEMAPHORE_NAMED_INSTVARS,
+	  HCL_CLASS_SPEC_FLAG_UNCOPYABLE,
+	  HCL_OBJ_TYPE_OOP,
+	  HCL_OFFSETOF(hcl_t, c_semaphore) },
+
+	{ "SemaphoreGroup",
+	  0,
+	  0,
+	  HCL_SEMAPHORE_GROUP_NAMED_INSTVARS,
+	  HCL_CLASS_SPEC_FLAG_UNCOPYABLE,
+	  HCL_OBJ_TYPE_OOP,
+	  HCL_OFFSETOF(hcl_t, c_semaphore_group) },
+
+	{ "ProcessScheduler",
+	  HCL_CLASS_SELFSPEC_FLAG_FINAL | HCL_CLASS_SELFSPEC_FLAG_LIMITED,
+	  0,
+	  HCL_PROCESS_SCHEDULER_NAMED_INSTVARS,
+	  HCL_CLASS_SPEC_FLAG_UNCOPYABLE,
+	  HCL_OBJ_TYPE_OOP,
+	  HCL_OFFSETOF(hcl_t, c_process_scheduler) },
+
+	{ "Error",
+	  HCL_CLASS_SELFSPEC_FLAG_LIMITED,
+	  0,
+	  0,
+	  0,
+	  HCL_OBJ_TYPE_OOP,
+	  HCL_OFFSETOF(hcl_t, c_error) },
+
+	{ "True",
+	  HCL_CLASS_SELFSPEC_FLAG_LIMITED | HCL_CLASS_SELFSPEC_FLAG_FINAL,
+	  0,
+	  0,
+	  0,
+	  HCL_OBJ_TYPE_OOP,
+	  HCL_OFFSETOF(hcl_t, c_true) },
+
+	{ "False",
+	  HCL_CLASS_SELFSPEC_FLAG_LIMITED | HCL_CLASS_SELFSPEC_FLAG_FINAL,
+	  0,
+	  0,
+	  0,
+	  HCL_OBJ_TYPE_OOP,
+	  HCL_OFFSETOF(hcl_t, c_false) },
+
+	/* TOOD: what is a proper spec for Character and SmallInteger?
+	 *       If the fixed part is  0, its instance must be an object of 0 payload fields.
+	 *       Does this make sense? */
+	{ "Character",
+	  HCL_CLASS_SELFSPEC_FLAG_LIMITED,
+	  0,
+	  0,
+	  0,
+	  HCL_OBJ_TYPE_OOP,
+	  HCL_OFFSETOF(hcl_t, c_character) },
+
+	{ "SmallInteger",
+	  HCL_CLASS_SELFSPEC_FLAG_LIMITED,
+	  0,
+	  0,
+	  0,
+	  HCL_OBJ_TYPE_OOP,
+	  HCL_OFFSETOF(hcl_t, c_small_integer) },
+
+	{ "LargePositiveInteger",
+	  HCL_CLASS_SELFSPEC_FLAG_LIMITED,
+	  0,
+	  0,
+	  HCL_CLASS_SPEC_FLAG_INDEXED | HCL_CLASS_SPEC_FLAG_IMMUTABLE,
+	  HCL_OBJ_TYPE_LIWORD,
+	  HCL_OFFSETOF(hcl_t, c_large_positive_integer) },
+
+	{ "LargeNegativeInteger",
+	  HCL_CLASS_SELFSPEC_FLAG_LIMITED,
+	  0,
+	  0,
+	  HCL_CLASS_SPEC_FLAG_INDEXED | HCL_CLASS_SPEC_FLAG_IMMUTABLE,
+	  HCL_OBJ_TYPE_LIWORD,
+	  HCL_OFFSETOF(hcl_t, c_large_negative_integer) },
+
+	{ "FixedPointDecimal",
+	  HCL_CLASS_SELFSPEC_FLAG_LIMITED,
+	  0,
+	  HCL_FPDEC_NAMED_INSTVARS,
+	  HCL_CLASS_SPEC_FLAG_IMMUTABLE,
+	  HCL_OBJ_TYPE_OOP,
+	  HCL_OFFSETOF(hcl_t, c_fixed_point_decimal) },
+
+	{ "SmallPointer",
+	  HCL_CLASS_SELFSPEC_FLAG_LIMITED,
+	  0,
+	  0,
+	  0,
+	  HCL_OBJ_TYPE_OOP,
+	  HCL_OFFSETOF(hcl_t, c_small_pointer) },
+
+	{ "LargePointer",
+	  HCL_CLASS_SELFSPEC_FLAG_LIMITED,
+	  0,
+	  1,  /* #word(1) */
+	  HCL_CLASS_SPEC_FLAG_IMMUTABLE | HCL_CLASS_SPEC_FLAG_INDEXED,
+	  HCL_OBJ_TYPE_WORD,
+	  HCL_OFFSETOF(hcl_t, c_large_pointer) },
+
+	{ "System",
+	  0,
+	  5, /* asyncsg, gcfin_sem, gcfin_should_exit, ossig_pid, shr */
+	  0,
+	  0,
+	  HCL_OBJ_TYPE_OOP,
+	  HCL_OFFSETOF(hcl_t, c_system) }
+};
+
+/* ========================================================================= */
+
 static void compact_symbol_table (hcl_t* hcl, hcl_oop_t _nil)
 {
 	hcl_oop_char_t symbol;
@@ -770,428 +1199,6 @@ hcl_oop_t hcl_shallowcopy (hcl_t* hcl, hcl_oop_t oop)
 
 /* ========================================================================= */
 
-static struct
-{
-	const char* name;
-	hcl_oow_t c_offset; /* class offset */
-	hcl_oow_t sc_offset; /* superclass offset */
-	hcl_oow_t nivars;
-	hcl_oow_t ncvars;
-} kctab[] = {
-	{ "Apex",
-	  HCL_OFFSETOF(hcl_t, c_apex),
-	  HCL_TYPE_MAX(hcl_oow_t),
-	  0, 0 },
-
-	{ "Object",
-	  HCL_OFFSETOF(hcl_t, c_object),
-	  HCL_OFFSETOF(hcl_t, c_apex),
-	  0, 0 },
-
-	{ "UndefinedObject",
-	  HCL_OFFSETOF(hcl_t, c_undefobj),
-	  HCL_OFFSETOF(hcl_t, c_apex),
-	  0, 0 },
-
-	{ "Class",
-	  HCL_OFFSETOF(hcl_t, c_class),
-	  HCL_OFFSETOF(hcl_t, c_object),
-	  HCL_CLASS_NAMED_INSTVARS, 0 },
-
-	{ "String",
-	  HCL_OFFSETOF(hcl_t, c_string),
-	  HCL_OFFSETOF(hcl_t, c_object),
-	  0, 0 },
-
-	{ "Symbol",
-	  HCL_OFFSETOF(hcl_t, c_symbol),
-	  HCL_OFFSETOF(hcl_t, c_string),
-	  0, 0 },
-
-	{ "Boolean",
-	  HCL_OFFSETOF(hcl_t, c_boolean),
-	  HCL_OFFSETOF(hcl_t, c_object),
-	  0, 0 },
-
-	{ "True",
-	  HCL_OFFSETOF(hcl_t, c_true),
-	  HCL_OFFSETOF(hcl_t, c_boolean),
-	  0, 0 },
-
-	{ "False",
-	  HCL_OFFSETOF(hcl_t, c_false),
-	  HCL_OFFSETOF(hcl_t, c_boolean),
-	  0, 0 },
-
-	{ "System",
-	  HCL_OFFSETOF(hcl_t, c_system),
-	  HCL_OFFSETOF(hcl_t, c_object),
-	  0, 0 },
-};
-
-
-/*
- *    Apex......................
- *    ^ ^ ^                    :   .......
- *    | | |                    v   v     :
- *    | | +------------------- Class .....
- *    | |                       ^  ^
- *    | +-------- NilObject ......:  :
- *    |                 ^........ nil  :
- *   Object ...........................:
- *    ^
- *    |
- *
- * The class hierarchy is roughly as follows:
- *
- *   Apex
- *      Class
- *      NilObject
- *      Object
- *         Collection
- *            IndexedCollection
- *               FixedSizedCollection
- *                  Array
- *                  ByteArray
- *                     String
- *                        Symbol
- *            Set
- *               Dictionary
- *                  SystemDictionary
- *               SymbolSet
- *         Magnitude
- *            Association
- *            Character
- *            Number
- *               Integer
- *                  SmallInteger
- *                  LargeInteger
- *                     LargePositiveInteger
- *                     LargeNegativeInteger
- *
- * Apex has no instance variables.
- *
- */
-
-struct kernel_class_info_t
-{
-	const hcl_bch_t* name;
-	int class_flags;
-	int class_num_classvars;
-
-	int class_spec_named_instvars;
-	int class_spec_flags;
-	int class_spec_indexed_type;
-
-	hcl_oow_t  offset;
-};
-typedef struct kernel_class_info_t kernel_class_info_t;
-
-static kernel_class_info_t kernel_classes[] =
-{
-	/* --------------------------------------------------------------
-	 * Apex            - proto-object with 1 class variable.
-	 * UndefinedObject - class for the nil object.
-	 * Object          - top of all ordinary objects.
-	 * String
-	 * Symbol
-	 * Array
-	 * ByteArray
-	 * SymbolSet
-	 * Character
-	 * SmallIntger
-	 * -------------------------------------------------------------- */
-
-	{ "Apex",
-	  0,
-	  0,
-	  0,
-	  0,
-	  HCL_OBJ_TYPE_OOP,
-	  HCL_OFFSETOF(hcl_t, c_apex) },
-
-	{ "UndefinedObject",
-	  0,
-	  0,
-	  0,
-	  0,
-	  HCL_OBJ_TYPE_OOP,
-	  HCL_OFFSETOF(hcl_t, c_undefobj) },
-
-#define KCI_CLASS 2 /* index to the Class entry in this table */
-	{ "Class",
-	  HCL_CLASS_SELFSPEC_FLAG_LIMITED,
-	  0,
-	  HCL_CLASS_NAMED_INSTVARS,
-	  HCL_CLASS_SPEC_FLAG_INDEXED | HCL_CLASS_SPEC_FLAG_UNCOPYABLE,
-	  HCL_OBJ_TYPE_OOP,
-	  HCL_OFFSETOF(hcl_t, c_class) },
-
-#if 0
-	{ "Interface",
-	  HCL_CLASS_SELFSPEC_FLAG_LIMITED,
-	  0,
-	  HCL_INTERFACE_NAMED_INSTVARS,
-	  HCL_CLASS_SPEC_FLAG_INDEXED | HCL_CLASS_SPEC_FLAG_UNCOPYABLE,
-	  HCL_OBJ_TYPE_OOP,
-	  HCL_OFFSETOF(hcl_t, _interface) },
-#endif
-
-	{ "Object",
-	  0,
-	  0,
-	  0,
-	  0,
-	  HCL_OBJ_TYPE_OOP,
-	  HCL_OFFSETOF(hcl_t, c_object) },
-
-	{ "String",
-	  0,
-	  0,
-	  0,
-	  HCL_CLASS_SPEC_FLAG_INDEXED,
-	  HCL_OBJ_TYPE_CHAR,
-	  HCL_OFFSETOF(hcl_t, c_string) },
-
-	{ "Symbol",
-	  HCL_CLASS_SELFSPEC_FLAG_FINAL | HCL_CLASS_SELFSPEC_FLAG_LIMITED,
-	  0,
-	  0,
-	  HCL_CLASS_SPEC_FLAG_INDEXED | HCL_CLASS_SPEC_FLAG_IMMUTABLE,
-	  HCL_OBJ_TYPE_CHAR,
-	  HCL_OFFSETOF(hcl_t, c_symbol) },
-
-	{ "Array",
-	  0,
-	  0,
-	  0,
-	  HCL_CLASS_SPEC_FLAG_INDEXED,
-	  HCL_OBJ_TYPE_OOP,
-	  HCL_OFFSETOF(hcl_t, c_array) },
-
-	{ "ByteArray",
-	  0,
-	  0,
-	  0,
-	  HCL_CLASS_SPEC_FLAG_INDEXED,
-	  HCL_OBJ_TYPE_BYTE,
-	  HCL_OFFSETOF(hcl_t, c_byte_array) },
-
-	{ "SymbolTable",
-	  0,
-	  0,
-	  HCL_DIC_NAMED_INSTVARS,
-	  0,
-	  HCL_OBJ_TYPE_OOP,
-	  HCL_OFFSETOF(hcl_t, c_symbol_table) },
-
-	{ "Dictionary",
-	  0,
-	  0,
-	  HCL_DIC_NAMED_INSTVARS,
-	  0,
-	  HCL_OBJ_TYPE_OOP,
-	  HCL_OFFSETOF(hcl_t, c_dictionary) },
-
-	{ "Association",
-	  0,
-	  0,
-	  HCL_ASSOCIATION_NAMED_INSTVARS,
-	  0,
-	  HCL_OBJ_TYPE_OOP,
-	  HCL_OFFSETOF(hcl_t, c_association) },
-
-#if 0
-	{ "Namespace",
-	  HCL_CLASS_SELFSPEC_FLAG_LIMITED,
-	  0,
-	  HCL_NSDIC_NAMED_INSTVARS,
-	  0,
-	  HCL_OBJ_TYPE_OOP,
-	  HCL_OFFSETOF(hcl_t, c_namespace) },
-
-	{ "PoolDictionary",
-	  0,
-	  0,
-	  HCL_DIC_NAMED_INSTVARS,
-	  0,
-	  HCL_OBJ_TYPE_OOP,
-	  HCL_OFFSETOF(hcl_t, c_pool_dictionary) },
-#endif
-
-	{ "MethodDictionary",
-	  0,
-	  0,
-	  HCL_DIC_NAMED_INSTVARS,
-	  0,
-	  HCL_OBJ_TYPE_OOP,
-	  HCL_OFFSETOF(hcl_t, c_method_dictionary) },
-
-	{ "CompiledMethod",
-	  0,
-	  0,
-	  HCL_METHOD_NAMED_INSTVARS,
-	  HCL_CLASS_SPEC_FLAG_INDEXED,
-	  HCL_OBJ_TYPE_OOP,
-	  HCL_OFFSETOF(hcl_t, c_method) },
-
-	{ "MethodSignature",
-	  0,
-	  0,
-	  HCL_METHSIG_NAMED_INSTVARS,
-	  HCL_CLASS_SPEC_FLAG_INDEXED,
-	  HCL_OBJ_TYPE_OOP,
-	  HCL_OFFSETOF(hcl_t, c_methsig) },
-
-	{ "CompiledBlock",
-	  0,
-	  0,
-	  HCL_BLOCK_NAMED_INSTVARS,
-	  0,
-	  HCL_OBJ_TYPE_OOP,
-	  HCL_OFFSETOF(hcl_t, c_block) },
-
-	{ "MethodContext",
-	  HCL_CLASS_SELFSPEC_FLAG_FINAL | HCL_CLASS_SELFSPEC_FLAG_LIMITED,
-	  0,
-	  HCL_CONTEXT_NAMED_INSTVARS,
-	  HCL_CLASS_SPEC_FLAG_INDEXED,
-	  HCL_OBJ_TYPE_OOP,
-	  HCL_OFFSETOF(hcl_t, c_method_context) },
-
-	{ "BlockContext"
-	  HCL_CLASS_SELFSPEC_FLAG_FINAL | HCL_CLASS_SELFSPEC_FLAG_LIMITED,
-	  0,
-	  HCL_CONTEXT_NAMED_INSTVARS,
-	  HCL_CLASS_SPEC_FLAG_INDEXED,
-	  HCL_OBJ_TYPE_OOP,
-	  HCL_OFFSETOF(hcl_t, c_block_context) },
-
-	{ "Process",
-	  HCL_CLASS_SELFSPEC_FLAG_FINAL | HCL_CLASS_SELFSPEC_FLAG_LIMITED,
-	  0,
-	  HCL_PROCESS_NAMED_INSTVARS,
-	  HCL_CLASS_SPEC_FLAG_INDEXED | HCL_CLASS_SPEC_FLAG_UNCOPYABLE,
-	  HCL_OBJ_TYPE_OOP,
-	  HCL_OFFSETOF(hcl_t, c_process) },
-
-	{ "Semaphore",
-	  0,
-	  0,
-	  HCL_SEMAPHORE_NAMED_INSTVARS,
-	  HCL_CLASS_SPEC_FLAG_UNCOPYABLE,
-	  HCL_OBJ_TYPE_OOP,
-	  HCL_OFFSETOF(hcl_t, c_semaphore) },
-
-	{ "SemaphoreGroup",
-	  0,
-	  0,
-	  HCL_SEMAPHORE_GROUP_NAMED_INSTVARS,
-	  HCL_CLASS_SPEC_FLAG_UNCOPYABLE,
-	  HCL_OBJ_TYPE_OOP,
-	  HCL_OFFSETOF(hcl_t, c_semaphore_group) },
-
-	{ "ProcessScheduler",
-	  HCL_CLASS_SELFSPEC_FLAG_FINAL | HCL_CLASS_SELFSPEC_FLAG_LIMITED,
-	  0,
-	  HCL_PROCESS_SCHEDULER_NAMED_INSTVARS,
-	  HCL_CLASS_SPEC_FLAG_UNCOPYABLE,
-	  HCL_OBJ_TYPE_OOP,
-	  HCL_OFFSETOF(hcl_t, c_process_scheduler) },
-
-	{ "Error",
-	  HCL_CLASS_SELFSPEC_FLAG_LIMITED,
-	  0,
-	  0,
-	  0,
-	  HCL_OBJ_TYPE_OOP,
-	  HCL_OFFSETOF(hcl_t, c_error) },
-
-	{ "True",
-	  HCL_CLASS_SELFSPEC_FLAG_LIMITED | HCL_CLASS_SELFSPEC_FLAG_FINAL,
-	  0,
-	  0,
-	  0,
-	  HCL_OBJ_TYPE_OOP,
-	  HCL_OFFSETOF(hcl_t, c_true) },
-
-	{ "False",
-	  HCL_CLASS_SELFSPEC_FLAG_LIMITED | HCL_CLASS_SELFSPEC_FLAG_FINAL,
-	  0,
-	  0,
-	  0,
-	  HCL_OBJ_TYPE_OOP,
-	  HCL_OFFSETOF(hcl_t, c_false) },
-
-	/* TOOD: what is a proper spec for Character and SmallInteger?
-	 *       If the fixed part is  0, its instance must be an object of 0 payload fields.
-	 *       Does this make sense? */
-	{ "Character",
-	  HCL_CLASS_SELFSPEC_FLAG_LIMITED,
-	  0,
-	  0,
-	  0,
-	  HCL_OBJ_TYPE_OOP,
-	  HCL_OFFSETOF(hcl_t, c_character) },
-
-	{ "SmallInteger",
-	  HCL_CLASS_SELFSPEC_FLAG_LIMITED,
-	  0,
-	  0,
-	  0,
-	  HCL_OBJ_TYPE_OOP,
-	  HCL_OFFSETOF(hcl_t, c_small_integer) },
-
-	{ "LargePositiveInteger",
-	  HCL_CLASS_SELFSPEC_FLAG_LIMITED,
-	  0,
-	  0,
-	  HCL_CLASS_SPEC_FLAG_INDEXED | HCL_CLASS_SPEC_FLAG_IMMUTABLE,
-	  HCL_OBJ_TYPE_LIWORD,
-	  HCL_OFFSETOF(hcl_t, c_large_positive_integer) },
-
-	{ "LargeNegativeInteger",
-	  HCL_CLASS_SELFSPEC_FLAG_LIMITED,
-	  0,
-	  0,
-	  HCL_CLASS_SPEC_FLAG_INDEXED | HCL_CLASS_SPEC_FLAG_IMMUTABLE,
-	  HCL_OBJ_TYPE_LIWORD,
-	  HCL_OFFSETOF(hcl_t, c_large_negative_integer) },
-
-	{ "FixedPointDecimal",
-	  HCL_CLASS_SELFSPEC_FLAG_LIMITED,
-	  0,
-	  HCL_FPDEC_NAMED_INSTVARS,
-	  HCL_CLASS_SPEC_FLAG_IMMUTABLE,
-	  HCL_OBJ_TYPE_OOP,
-	  HCL_OFFSETOF(hcl_t, c_fixed_point_decimal) },
-
-	{ "SmallPointer",
-	  HCL_CLASS_SELFSPEC_FLAG_LIMITED,
-	  0,
-	  0,
-	  0,
-	  HCL_OBJ_TYPE_OOP,
-	  HCL_OFFSETOF(hcl_t, c_small_pointer) },
-
-	{ "LargePointer",
-	  HCL_CLASS_SELFSPEC_FLAG_LIMITED,
-	  0,
-	  1,  /* #word(1) */
-	  HCL_CLASS_SPEC_FLAG_IMMUTABLE | HCL_CLASS_SPEC_FLAG_INDEXED,
-	  HCL_OBJ_TYPE_WORD,
-	  HCL_OFFSETOF(hcl_t, c_large_pointer) },
-
-	{ "System",
-	  0,
-	  5, /* asyncsg, gcfin_sem, gcfin_should_exit, ossig_pid, shr */
-	  0,
-	  0,
-	  HCL_OBJ_TYPE_OOP,
-	  HCL_OFFSETOF(hcl_t, c_system) }
-};
-
-
 #if 0
 
 static hcl_oow_t move_finalizable_objects (hcl_t* hcl);
diff --git a/lib/hcl-prv.h b/lib/hcl-prv.h
index 632a158..b793ed8 100644
--- a/lib/hcl-prv.h
+++ b/lib/hcl-prv.h
@@ -150,6 +150,128 @@
 #	define HCL_OBJ_SIZE_BITS_MAX (HCL_OBJ_SIZE_MAX * HCL_BITS_PER_BYTE)
 #endif
 
+/* ========================================================================= */
+/* CLASS SPEC ENCODING                                                       */
+/* ========================================================================= */
+/*
+ * The spec field of a class object encodes the number of the fixed part
+ * and the type of the indexed part. The fixed part is the number of
+ * named instance variables. If the spec of a class is indexed, the object
+ * of the class can be instantiated with the size of the indexed part.
+ *
+ * For example, on a platform where sizeof(hcl_oow_t) is 4,
+ * the layout of the spec field of a class as an OOP value looks like this:
+ *
+ *  31                          12 11  10 9 8 7 6 5 4 3 2   1 0
+ * |number of named instance variables|indexed-type|flags |oop-tag|
+ *
+ * the number of named instance variables is stored in high 21 bits.
+ * the indexed type takes up bit 5 to bit 10 (assuming HCL_OBJ_TYPE_BITS is 6.
+ * HCL_OBJ_TYPE_XXX enumerators are used to represent actual values).
+ * and the indexability is stored in the flag bits which span from bit 2 to 4.
+ *
+ * The maximum number of named(fixed) instance variables for a class is:
+ *     2 ^ ((BITS-IN-OOW - HCL_OOP_TAG_BITS_LO) - HCL_OBJ_TYPE_BITS - 1 - 2) - 1
+ *
+ * HCL_OOP_TAG_BITS_LO are decremented from the number of bits in OOW because
+ * the spec field is always encoded as a small integer.
+ *
+ * The number of named instance variables can be greater than 0 if the
+ * class spec is not indexed or if it's a pointer indexed class
+ * (indexed_type == HCL_OBJ_TYPE_OOP)
+ *
+ * indexed_type is one of the #hcl_obj_type_t enumerators.
+ */
+
+#define HCL_CLASS_SPEC_FLAG_BITS (3)
+
+/*
+ * The HCL_CLASS_SPEC_MAKE() macro creates a class spec value.
+ *  _class->spec = HCL_SMOOI_TO_OOP(HCL_CLASS_SPEC_MAKE(0, 1, HCL_OBJ_TYPE_CHAR));
+ */
+#define HCL_CLASS_SPEC_MAKE(named_instvar,flags,indexed_type) ( \
+	(((hcl_oow_t)(named_instvar)) << (HCL_OBJ_FLAGS_TYPE_BITS + HCL_CLASS_SPEC_FLAG_BITS)) |  \
+	(((hcl_oow_t)(indexed_type)) << (HCL_CLASS_SPEC_FLAG_BITS)) | (((hcl_oow_t)flags) & HCL_LBMASK(hcl_oow_t,HCL_CLASS_SPEC_FLAG_BITS)))
+
+/* what is the number of named instance variables?
+ *  HCL_CLASS_SPEC_NAMED_INSTVARS(HCL_OOP_TO_SMOOI(_class->spec))
+ * ensure to update Class<<specNumInstVars if you change this macro. */
+#define HCL_CLASS_SPEC_NAMED_INSTVARS(spec) \
+	(((hcl_oow_t)(spec)) >> (HCL_OBJ_FLAGS_TYPE_BITS + HCL_CLASS_SPEC_FLAG_BITS))
+
+/* is it a user-indexable class?
+ * all objects can be indexed with basicAt:.
+ * this indicates if an object can be instantiated with a dynamic size
+ * (new: size) and and can be indexed with at:.
+ */
+#define HCL_CLASS_SPEC_FLAGS(spec) (((hcl_oow_t)(spec)) & HCL_LBMASK(hcl_oow_t,HCL_CLASS_SPEC_FLAG_BITS))
+
+/* if so, what is the indexing type? character? pointer? etc? */
+#define HCL_CLASS_SPEC_INDEXED_TYPE(spec) \
+	((((hcl_oow_t)(spec)) >> HCL_CLASS_SPEC_FLAG_BITS) & HCL_LBMASK(hcl_oow_t, HCL_OBJ_FLAGS_TYPE_BITS))
+
+#define HCL_CLASS_SPEC_FLAG_INDEXED    (1 << 0)
+#define HCL_CLASS_SPEC_FLAG_IMMUTABLE  (1 << 1)
+#define HCL_CLASS_SPEC_FLAG_UNCOPYABLE (1 << 2)
+
+#define HCL_CLASS_SPEC_IS_INDEXED(spec) (HCL_CLASS_SPEC_FLAGS(spec) & HCL_CLASS_SPEC_FLAG_INDEXED)
+#define HCL_CLASS_SPEC_IS_IMMUTABLE(spec) (HCL_CLASS_SPEC_FLAGS(spec) & HCL_CLASS_SPEC_FLAG_IMMUTABLE)
+#define HCL_CLASS_SPEC_IS_UNCOPYABLE(spec) (HCL_CLASS_SPEC_FLAGS(spec) & HCL_CLASS_SPEC_FLAG_UNCOPYABLE)
+
+/* What is the maximum number of named instance variables?
+ * This limit is set this way because the number must be encoded into
+ * the spec field of the class with limited number of bits assigned to
+ * the number of named instance variables.
+ */
+#define HCL_MAX_NAMED_INSTVARS \
+	HCL_BITS_MAX(hcl_oow_t, HCL_SMOOI_ABS_BITS - (HCL_OBJ_FLAGS_TYPE_BITS + HCL_CLASS_SPEC_FLAG_BITS))
+
+/* Given the number of named instance variables, what is the maximum number
+ * of indexed instance variables? The number of indexed instance variables
+ * is not stored in the spec field of the class. It only affects the actual
+ * size of an object(obj->_size) selectively combined with the number of
+ * named instance variables. So it's the maximum value of obj->_size minus
+ * the number of named instance variables.
+ */
+#define HCL_MAX_INDEXED_INSTVARS(named_instvar) (HCL_OBJ_SIZE_MAX - named_instvar)
+
+/*
+ * self-specification of a class
+ *   | classinstvars     | classvars         | flags |
+ *
+ * When converted to a small integer
+ *   | sign-bit | classinstvars | classvars | flags | tag |
+ */
+#define HCL_CLASS_SELFSPEC_FLAG_BITS (3)
+#define HCL_CLASS_SELFSPEC_CLASSINSTVAR_BITS ((HCL_SMOOI_ABS_BITS - HCL_CLASS_SELFSPEC_FLAG_BITS) / 2)
+#define HCL_CLASS_SELFSPEC_CLASSVAR_BITS (HCL_SMOOI_ABS_BITS - (HCL_CLASS_SELFSPEC_CLASSINSTVAR_BITS + HCL_CLASS_SELFSPEC_FLAG_BITS))
+
+#define HCL_CLASS_SELFSPEC_MAKE(class_var,classinst_var,flag) \
+	((((hcl_oow_t)class_var)     << (HCL_CLASS_SELFSPEC_CLASSINSTVAR_BITS + HCL_CLASS_SELFSPEC_FLAG_BITS)) | \
+	 (((hcl_oow_t)classinst_var) << (HCL_CLASS_SELFSPEC_FLAG_BITS)) | \
+	 (((hcl_oow_t)flag)          << (0)))
+
+#define HCL_CLASS_SELFSPEC_CLASSVARS(spec) \
+	(((hcl_oow_t)spec) >> (HCL_CLASS_SELFSPEC_CLASSINSTVAR_BITS + HCL_CLASS_SELFSPEC_FLAG_BITS))
+
+#define HCL_CLASS_SELFSPEC_CLASSINSTVARS(spec) \
+	((((hcl_oow_t)spec) >> HCL_CLASS_SELFSPEC_FLAG_BITS) & HCL_LBMASK(hcl_oow_t, HCL_CLASS_SELFSPEC_CLASSINSTVAR_BITS))
+
+#define HCL_CLASS_SELFSPEC_FLAGS(spec) \
+	(((hcl_oow_t)spec) & HCL_LBMASK(hcl_oow_t, HCL_CLASS_SELFSPEC_FLAG_BITS))
+
+#define HCL_CLASS_SELFSPEC_FLAG_FINAL   (1 << 0)
+#define HCL_CLASS_SELFSPEC_FLAG_LIMITED (1 << 1)
+
+
+#define HCL_MAX_CLASSVARS      HCL_BITS_MAX(hcl_oow_t, HCL_CLASS_SELFSPEC_CLASSVAR_BITS)
+#define HCL_MAX_CLASSINSTVARS  HCL_BITS_MAX(hcl_oow_t, HCL_CLASS_SELFSPEC_CLASSINSTVAR_BITS)
+
+/* ========================================================================= */
+/* END OF CLASS SPEC ENCODING                                                */
+/* ========================================================================= */
+
+
 
 #if defined(HCL_INCLUDE_COMPILER)
 
diff --git a/lib/hcl.h b/lib/hcl.h
index 20ec992..1e3fbf6 100644
--- a/lib/hcl.h
+++ b/lib/hcl.h
@@ -1649,17 +1649,19 @@ struct hcl_t
 	hcl_oop_class_t c_symbol; /* Symbol */
 	hcl_oop_class_t c_array; /* Array */
 	hcl_oop_class_t c_byte_array; /* ByteArray */
-	hcl_oop_class_t c_symbol_table; /* SymbolTable */
+	hcl_oop_class_t c_symtab; /* SymbolTable */
 	hcl_oop_class_t c_dictionary;
-	hcl_oop_class_t c_association; /* Association */
+	hcl_oop_class_t c_cons; /* Cons */
 
 #if 0
 	hcl_oop_class_t c_namespace; /* Namespace */
 	hcl_oop_class_t c_pool_dictionary; /* PoolDictionary */
 #endif
 	hcl_oop_class_t c_method_dictionary; /* MethodDictionary */
+#if 0
 	hcl_oop_class_t c_method; /* CompiledMethod */
 	hcl_oop_class_t c_methsig; /* MethodSignature */
+#endif
 	hcl_oop_class_t c_block; /* CompiledBlock */
 
 	hcl_oop_class_t c_method_context; /* MethodContext */