 The temporary variable "t" holds the value of "r""k"−1 while the next remainder "r""k" is being calculated.At the end of the loop iteration, the variable "b" holds the remainder "r""k", whereas the variable "a" holds its predecessor, "r""k"−1.In the subtraction-based version which was Euclid's original version, the remainder calculation (codice_1) is replaced by repeated subtraction.