| Replace of loc * ('term, 'lazy_term, 'ident) pattern * 'lazy_term
| Rewrite of loc * direction * 'term *
('term, 'lazy_term, 'ident) pattern * 'ident list
| Replace of loc * ('term, 'lazy_term, 'ident) pattern * 'lazy_term
| Rewrite of loc * direction * 'term *
('term, 'lazy_term, 'ident) pattern * 'ident list