plus vs. minus

[Ralf Hemmecke]

Hi Waldek,

isn't this behaviour (depending on + or - a bit weird?
Why is fricas trying to look for an elt with SINT instead of PI

(MODFUNC(FRAC(INT),[[[1,0],[0,1]]]), SINT)

FriCAS should clearly know that d is (or can be coerced to PI so why not
trying that in the (f-f) case?

Ralf


(255) -> d

(255) 1
Type:
PositiveInteger


(253) -> (f + f).d

Function Selection for +
Arguments: (MODFUNC(FRAC(INT),[[[1,0],[0,1]]]),
MODFUNC(FRAC(INT),[[[1,0],[0,1]]]))

[1] signature: (MODFUNC(FRAC(INT),[[[1,0],[0,1]]]),
MODFUNC(FRAC(INT),[[[1,0],[0,1]]])) -> MODFUNC(FRAC(INT),[[[1,0],[0,1]]])
implemented: slot $$$ from MODFUNC(FRAC(INT),[[[1,0],[0,1]]])


Function Selection for elt
Arguments: (MODFUNC(FRAC(INT),[[[1,0],[0,1]]]), PI)

[1] signature: (MODFUNC(FRAC(INT),[[[1,0],[0,1]]]), PI) ->
QETALS(FRAC(INT))
implemented: slot (QEtaLaurentSeries (Fraction
(Integer)))$(PositiveInteger) from MODFUNC(FRAC(INT),[[[1,0],[0,1]]])


Function Selection for elt
Arguments: (MODFUNC(FRAC(INT),[[[1,0],[0,1]]]), PI)

[1] signature: (MODFUNC(FRAC(INT),[[[1,0],[0,1]]]), PI) ->
QETALS(FRAC(INT))
implemented: slot (QEtaLaurentSeries (Fraction
(Integer)))$(PositiveInteger) from MODFUNC(FRAC(INT),[[[1,0],[0,1]]])


3 4
(253) 2 q + 8 q + O(q )
Type:
QEtaLaurentSeries(Fraction(Integer))
(254) -> (f - f).d

Function Selection for -
Arguments: (MODFUNC(FRAC(INT),[[[1,0],[0,1]]]),
MODFUNC(FRAC(INT),[[[1,0],[0,1]]]))

[1] signature: (MODFUNC(FRAC(INT),[[[1,0],[0,1]]]),
MODFUNC(FRAC(INT),[[[1,0],[0,1]]])) -> MODFUNC(FRAC(INT),[[[1,0],[0,1]]])
implemented: slot $$$ from MODFUNC(FRAC(INT),[[[1,0],[0,1]]])


Function Selection for elt
Arguments: (MODFUNC(FRAC(INT),[[[1,0],[0,1]]]), SINT)
-> no function elt found for arguments
(MODFUNC(FRAC(INT),[[[1,0],[0,1]]]), SINT)

Function Selection for apply
Arguments: (MODFUNC(FRAC(INT),[[[1,0],[0,1]]]), SINT)
-> no function apply found for arguments
(MODFUNC(FRAC(INT),[[[1,0],[0,1]]]), SINT)
There are 1 exposed and 1 unexposed library operations named elt
having 1 argument(s) but none was determined to be applicable.
Use HyperDoc Browse, or issue
)display op elt
to learn more about the available operations. Perhaps
package-calling the operation or using coercions on the arguments
will allow you to apply the operation.

Cannot find application of object of type
ModularFunctionExpansionsAtCusps(Fraction(Integer),[[[1,0],[0,1]]
]) to argument(s) of type(s)
PositiveInteger

(254) -> elt(f - f, d)

Function Selection for -
Arguments: (MODFUNC(FRAC(INT),[[[1,0],[0,1]]]),
MODFUNC(FRAC(INT),[[[1,0],[0,1]]]))

[1] signature: (MODFUNC(FRAC(INT),[[[1,0],[0,1]]]),
MODFUNC(FRAC(INT),[[[1,0],[0,1]]])) -> MODFUNC(FRAC(INT),[[[1,0],[0,1]]])
implemented: slot $$$ from MODFUNC(FRAC(INT),[[[1,0],[0,1]]])


Function Selection for elt
Arguments: (MODFUNC(FRAC(INT),[[[1,0],[0,1]]]), PI)

[1] signature: (MODFUNC(FRAC(INT),[[[1,0],[0,1]]]), PI) ->
QETALS(FRAC(INT))
implemented: slot (QEtaLaurentSeries (Fraction
(Integer)))$(PositiveInteger) from MODFUNC(FRAC(INT),[[[1,0],[0,1]]])


6
(254) O(q )
Type:
QEtaLaurentSeries(Fraction(Integer))

[Waldek Hebisch]

On Fri, Mar 31, 2023 at 01:49:45PM +0200, Ralf Hemmecke wrote:
> Hi Waldek,
>
> isn't this behaviour (depending on + or - a bit weird?
> Why is fricas trying to look for an elt with SINT instead of PI
>
> (MODFUNC(FRAC(INT),[[[1,0],[0,1]]]), SINT)
>
> FriCAS should clearly know that d is (or can be coerced to PI so why not
> trying that in the (f-f) case?

That looks like a bug.

--
Waldek Hebisch