bool EvalAnd(string val) { if (val.IndexOf('&') != -1) { var ands = val.Split('&'); foreach (var tag in ands) { var id = MSBuildProjectService.ConvertTypeAliasToGuid(tag.Trim()); if (!tags.Contains(id)) { return(false); } } return(true); } return(tags.Contains(MSBuildProjectService.ConvertTypeAliasToGuid(val.Trim()))); }