id summary reporter owner description type status priority milestone component resolution keywords cc merged author reviewer upstream work_issues branch commit dependencies stopgaps
18832 non-numeric non-symbolic BuiltinFunction arguments rws "Symbolic expressions can be seen as programs for applying functions to numerics and symbolics. Non-numeric non-symbolics (NNNS, most of the rest of Sage) are usually not handled by symbolic functions, although they often allow the same operations and many of the functions. The manual workaround is to evaluate the expression ""on `x`"" and then to substitute `x` with the respective NNNS. We propose that `BuiltinFunction` automates this process.
Part of this is already duplicated in `rings.arith` but the need arises with symbolic functions returning polynomials, e.g. #16813. At the moment `BuiltinFunction` simply converts the NNNS argument, losing the type information.
Practically, `BuiltinFunction` should eval with `x`, try substitution, and throw an error if the substitution leads to unknown methods of the NNNS. I.e.
{{{
sage: elliptic_f (x, 1)
log(tan(1/4*pi + 1/2*x))
sage: elliptic_f (polygen(CC), 1)
...
AttributeError: cannot apply function to argument x: argument does not know how to do log
(coming from this exception)
AttributeError: 'Polynomial_generic_dense_field' object has no attribute 'log'
}}}" defect closed major sage-duplicate/invalid/wontfix symbolics fixed jdemeyer N/A #20312