+/* The worker for optional_context_mods conses a (reversed) list where
+ * each element contains the list of single context mods from one
+ * context modification block. Context_mod::get_mods creates fresh
+ * copies, so it's okay to use append! on them.
+ */
+
+context_modification_mods_list:
+ /**/ {
+ $$ = SCM_EOL;
+ }
+ | context_modification_mods_list context_modification
+ {
+ if (Context_mod *m = unsmob<Context_mod> ($2))
+ $$ = scm_cons (m->get_mods (), $1);
+ }
+ ;
+
+/* A Context_mod is a container for a list of context mods like
+ * \consists ... \override ... . context_mod_list produces a
+ * Context_mod from the inside of a \with { ... } statement.
+ */
+