Opened 2 years ago

Closed 2 years ago

## #871 closed bug (not a bug)

# Documentation in rings does not tell the whole story

Reported by: | Owned by: | somebody | |
---|---|---|---|

Priority: | minor | Milestone: | 4-2-1 and higher |

Component: | dontKnow | Version: | 4-2-0 |

Keywords: | Cc: |

### Description

For version 4.2.0, the documentation declares that the possible prime characteristics are and "non-negative int_expression less or equal 2147483647".

The version 4.2.0 on my computer does not believe this.
I am able to do some calculations in characteristic 1073741789 (=prime(2^{30)), but when I try to factorize a univariate polynomial in such a ring with the command: L= factorize(f,1);, I get the error message:
}

? characteristic is too large(max is 2

^{29) ? not implemented ? error occurred in or before STDIN line 50: L= factorize(f,1); }

-Frank Sottile

Here is a session: sottile: Singular

SINGULAR /

A Computer Algebra System for Polynomial Computations / version 4.2.0

0<

by: W. Decker, G.-M. Greuel, G. Pfister, H. Schoenemann \ Dec 2020

FB Mathematik der Universitaet, D-67653 Kaiserslautern \

ring r = 1073741789, (x), dp; poly f= (30+251*x)

^{10; factorize(f,1); }

? characteristic is too large(max is 2

^{29) ? not implemented ? error occurred in or before STDIN line 3: factorize(f,1); }

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see Limitations (https://www.singular.uni-kl.de/Manual/4-2-0/sing_411.htm)

the characteristic of a prime field must be less than or equal to 2147483647 (2* *31) (the characteristic of a prime field in the factory routines must be less than 536870912 (2* *29)) (the characteristic of a prime field in the NTL routines must be less than NTL_SP_BOUND (2* *30) on 32bit machines - This is always the case since currently, only factory uses NTL.)

Thanks for the hint, I will add a pointer to this to the ring chapter.