As I said there:

https://www.mapleprimes.com/questions/230574-Bug-In-Modp1Rem

this bug still appear.

@dohashi 

@TechnicalSupport 

Hi.

I'm wondering that this bug still not fixed in Maple 2021 (as it didn't fix in Maple 2020.2) for win64.

New link of file polys.m

https://dropmefiles.com/yI3D5

Bug with Embed too:

https://www.mapleprimes.com/questions/230609-Bug-In-Modp1Embed

Hope you'll fix them.

Thank you.

@tomleslie 

Thank you

@ecterrab 

Thank you

@Carl Love 

> It's not possible to calculate a middle coefficient of the product without fully scanning all coefficients of the multiplicands.

Yeah, I know. But calculating of any range of product's coefficients should be more efficient than calculating of all coefficients. Even if a range consists middle coefficients that need all coefficients of multiplicands.

@Carl Love 

I tried with converting polynomials to lists and using add function - too unefficient. So I'm sure it should be low-level (like a modp1(('Multiply')(...)) ) solution.

> to compute the first n leading or trailing coefficients of a polynomial multiplication

Not only this but any range of coefficients in the middle of a polynomial too.

Hi.

Any comments?

@acer 

Yes, exactly

@rookie 

But don't in Maple 2020

Thank you all.

If you need to save a polynomial with many big coefficients only a way with m-files is suite. But m-files have some disadvantage - they're not readable.

@TechnicalSupport 

Thank you!

@dohashi 

Have you any news about fixing?

@dohashi 

Thank you

@vv 

It's idea

@dohashi 

Please: