void Decode_Click(object sender, RoutedEventArgs e) {
			var trace = stackTrace.Text;
			if (optSym.IsChecked ?? true)
				stackTrace.Text = mapSymbolMatcher.Replace(trace, DecodeSymbolMap);
			else {
				renamer = new ReversibleRenamer(PassBox.Text);
				stackTrace.Text = passSymbolMatcher.Replace(trace, DecodeSymbolPass);
			}
		}