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- To: common-lisp@su-ai
- Subject: gaussian rationals
- From: fateman%UCBKIM@Berkeley (Richard Fateman)
- Date: Sun, 05 Jun 1983 15:13:00 -0000
Frankly, complex arithmetic should not be designed by a consensus of Lisp
hackers. The difference between mathematical theory and computation
is perhaps not clear to Alan, but there is a difference between thinking
mathematically and computationally. For example, division by 0 is not
defined in a mathematical field. Computationally, division by 0 must
be treated SOME way. Similarly, -1 and -1+0*i can be said to be mathematically
identical, but that says very little about how to compute with them.
In particular, whether sqrt(*) gives an error or not. One view of
sqrt(-4) is that it should return -2. The sign of the answer clearly indicates
something funny went on.
I would propose that rather than vote on complex arithmetic in this forum,
real arithmetic only be specified, and allow someone at some later
time specify a package for complex.