tactic: [
[ IDENT "absurd"; t = tactic_term ->
GrafiteAst.Absurd (loc, t)
+ | IDENT "apply"; IDENT "rule"; t = tactic_term ->
+ GrafiteAst.ApplyRule (loc, t)
| IDENT "apply"; t = tactic_term ->
GrafiteAst.Apply (loc, t)
| IDENT "applyP"; t = tactic_term ->