PARSER->lexer_->set_identifier (ly_symbol2scm ("$current-book"), $$->self_scm ());
PARSER->lexer_->set_identifier (ly_symbol2scm ("book-output-suffix"), SCM_BOOL_F);
PARSER->lexer_->set_identifier (ly_symbol2scm ("book-filename"), SCM_BOOL_F);
PARSER->lexer_->set_identifier (ly_symbol2scm ("$current-book"), $$->self_scm ());
PARSER->lexer_->set_identifier (ly_symbol2scm ("book-output-suffix"), SCM_BOOL_F);
PARSER->lexer_->set_identifier (ly_symbol2scm ("book-filename"), SCM_BOOL_F);