Index: ossp-pkg/l2/l2_spec_ebnf
RCS File: /v/ossp/cvs/ossp-pkg/l2/Attic/l2_spec_ebnf,v
co -q -kk -p'1.1' '/v/ossp/cvs/ossp-pkg/l2/Attic/l2_spec_ebnf,v' | diff -u /dev/null - -L'ossp-pkg/l2/l2_spec_ebnf' 2>/dev/null
--- ossp-pkg/l2/l2_spec_ebnf
+++ -	2024-05-02 19:14:30.943674981 +0200
@@ -0,0 +1,39 @@
+tree : stream                                              /* channel tree */
+    ;
+
+stream : channel                                     /* stream of channels */
+    | channel T_OP_ARROW stream
+    | channel T_OP_ARROW '{' streams '}'
+    ;
+
+streams : stream                                /* list of sibling streams */
+    | stream ';' streams
+    ;
+
+channel : channel_level '/' channel_level ':' channel_cons      /* channel */
+    | channel_level ':' channel_cons
+    | channel_cons
+    ;
+
+channel_level : T_ID                                      /* channel level */
+    | '(' channel_level_mask ')'
+    ;
+
+channel_level_mask : T_ID                            /* channel level mask */
+    | T_ID '|' channel_level_mask
+    ;
+
+channel_cons : T_ID                                 /* channel constructor */
+    ;
+
+channel_params : /* empty */                         /* channel parameters */
+    | '(' channel_param_list ')'
+    ;
+
+channel_param_list : /* empty */                 /* channel parameter list */
+    | channel_param
+    | channel_param ',' channel_param_list
+    ;
+
+channel_param  : T_ID '='                             /* channel parameter */
+    ;