TY - JOUR AU - Bergstra, Jan Aldert AU - Tucker, John V. PY - 2020/12/16 Y2 - 2024/03/28 TI - The Transrational Numbers as an Abstract Data Type JF - Transmathematica JA - Transmath VL - 0 IS - 0 SE - Primary Article DO - 10.36285/tm.47 UR - https://transmathematica.org/index.php/journal/article/view/47 SP - AB - <p>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.</p> ER -