The Transrational Numbers as an Abstract Data Type


  • Jan Aldert Bergstra University of Amsterdam
  • John V. Tucker Swansea University



rational numbers, arithmetical structures, division by zero, meadows, wheels, transrationals, equational specification, initial algebra semantics


In an arithmetical structure one can make division a total function by defining 1/0 to be an element of the structure, or by adding a new element, such as an error element also denoted with a new constant symbol, an unsigned infinity or one or both signed infinities, one positive and one negative. We define an enlargement of a field to a transfield, in which division is totalised by setting 1/0 equal to the positive infinite value and -1/0 equal to its opposite, and which also contains an error element to help control their effects. We construct the transrational numbers as a transfield of the field of rational numbers and consider it as an abstract data type. We give it an equational specification under initial algebra semantics.




How to Cite

Bergstra, J. A., & Tucker, J. V. (2020). The Transrational Numbers as an Abstract Data Type. Transmathematica.



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