This form serves to convert numbers between number systems of different bases (decimal has base 10, binary has base 2, etc.) A repeating fraction is put between {}, so 10,11{45} means 10,11454545454545454545....
To separate integers from the fraction, you can use ,.:; To indicate a repeating fraction, put it between {}\[]
Input is rather tolerant: You may exceed the maximum value for a digit. For example, in the decimal system, you may write "a" in stead of "10". And in the system that has base 5, you may write "7" in stead of "12". This will simply cause an overflow to the more significant position.