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## [Axiom-developer] [#193 Symbolic values (without variables) are not orde

 From: wyscc Subject: [Axiom-developer] [#193 Symbolic values (without variables) are not ordered properly in 'EXPR INT'] Two different orderings mixed up Date: Thu, 21 Jul 2005 00:08:30 -0500

```Changes
http://page.axiom-developer.org/zope/mathaction/193SymbolicValuesWithoutVariablesAreNotOrderedProperlyInEXPRINT/diff
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??changed:
-(This is reminescent of FORTRAN: type promotion from INTEGER to REAL). In
other words, if one wants to test numerical inequalities involving symbolic
constants, one should work in 'EXPR Float', not 'EXPR Integer' since most
symbolic constants are not integers. To provide an automatic type promotion
from 'EXPR INT' to 'EXPR Float' would interfere with the ordering in polynomial
expressions, unless a symbolic constant can be distinguished from a polynomial
variable. We cannot overload the operator '<' for two distinct orderings in the
same domain. I think the suggestion I posted in #47 of a 'SymbolicFloat' domain
may be worth exploring. In 'SymbolicFloat', we can retain symbolic manipulation
of expresions with symbolic constants by using the term-ordering of the
underllying representation, and still use the numerical ordering of the domain
'SymbolicFloat'.
(This is reminescent of FORTRAN: type promotion from INTEGER to REAL). In other
words, if one wants to test numerical inequalities involving symbolic
constants, one should work in 'EXPR Float', not 'EXPR Integer' since most
symbolic constants are not integers. To provide an automatic type promotion
from 'EXPR INT' to 'EXPR Float' would interfere with the ordering in polynomial
expressions, unless a symbolic constant can be distinguished from a polynomial
variable. We cannot overload the operator '<' for two distinct orderings in the
same domain. I think the suggestion I posted in #47 of a 'SymbolicFloat' domain
may be worth exploring. In 'SymbolicFloat', we can retain symbolic manipulation
of expressions with symbolic constants by using the term-ordering of the
underlying representation, and still use the numerical ordering of the domain
'SymbolicFloat'.

--
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```

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