In the attached exemple, the DELETE_RULE raise an exception Not_found. The statement DELETE_RULE Gram foo: "foo"; LIDENT; END bar is exploded as follows : $ camlp4of -str "DELETE_RULE Gram foo: "foo"; LIDENT; bar END" Gram.delete_rule foo [ Gram.Snterm (Gram.Entry.obj (foo : 'foo Gram.Entry.t)); Gram.Stoken (((function | LIDENT ((_)) -> true | _ -> false), "LIDENT ((_))")); Gram.Snterm (Gram.Entry.obj (bar : 'bar Gram.Entry.t)) ] while the running example is the following : Gram.delete_rule foo [ Gram.Skeyword "foo"; Gram.Stoken (((function | LIDENT ((_)) -> true | _ -> false), "LIDENT _")); Gram.Snterm (Gram.Entry.obj (bar : 'bar Gram.Entry.t)) ] How do I write the rule DELETE_RULE to work in this case? -- Serge Leblanc gpg --keyserver hkp://keyserver.ubuntu.com:11371 --recv-keys 0x33243C1B Fingerprint = 066C 005F 5595 D85C 7673 D969 1DD4 90C4 3324 3C1B