private TriggerAnnotation AnnotateMatchExpr(MatchExpr expr)
{
var pts = CollectExportedCandidates(expr);
// collects that argument boundvar of matchcaseexpr
var variables = expr.Cases.Select(e => e.Arguments).
Aggregate(new List<BoundVar>(), (acc, e) => TriggerUtils.MergeAlterFirst(acc, e));
// remove terms that mentions argument boundvar of matchcaseexpr
var terms = new List<TriggerTerm>();
foreach (var term in pts) {
if (!(variables.All(x => term.Variables.Contains(x)))) {
terms.Add(term);
}
}
return new TriggerAnnotation(true, CollectVariables(expr), terms);
}