As Britain tries to withdraw from the European Union, the move is presenting complex problems for some in the financial industry. Computer trading systems in the international currency markets are struggling to make sense of all the hourly information. This overload, some say, is making it more costly and risky to trade the British currency, the pound. Prime Minister Theresa May has failed three times to get a deal approved by the British parliament to leave the EU. Last week, she sent a letter to the European Council. She asked for a delay of Britain’s proposed withdrawal. European Council President Donald Tusk reacted by suggesting a delay of one year. No one knows when, how or if Britain will truly complete “Brexit,” the British exit from the group. Britain’s government is divided over the issue, and the number of people who can influence events has grown very large.