(match (pat, terms) with
| None, [] -> TacticAst.Reduce (loc, kind, None)
| None, terms -> TacticAst.Reduce (loc, kind, Some (terms, `Goal))
(match (pat, terms) with
| None, [] -> TacticAst.Reduce (loc, kind, None)
| None, terms -> TacticAst.Reduce (loc, kind, Some (terms, `Goal))