| Try of loc * ('term, 'lazy_term, 'reduction, 'ident) tactical
(* try a tactical and mask failures *)
| Solve of loc * ('term, 'lazy_term, 'reduction, 'ident) tactical list
+ | Progress of loc * ('term, 'lazy_term, 'reduction, 'ident) tactical
| Dot of loc
| Semicolon of loc