Opened 6 years ago

Last modified 6 years ago

#799 new bug

minres() does not minimize first module

Reported by: steenpass Owned by: decker
Priority: minor Milestone: 4-2-0 and higher
Component: singular-kernel Version: 4-1-0
Keywords: minres Cc:

Description

Consider the following example:

> ring r = 0, (x,y), dp;
> module m = x*gen(1)+gen(2), y*gen(2);
> resolution s = res(m, 0);
> print(betti(s, 0), "betti");
           0     1
------------------
    0:     1     1
    1:     1     1
------------------
total:     2     2

> print(betti(s, 1), "betti");
           0     1
------------------
    0:     1     -
    1:     -     1
------------------
total:     1     1

> resolution s_min = minres(s);
> print(betti(s_min, 0), "betti");
           0     1
------------------
    0:     1     1
    1:     1     1
------------------
total:     2     2

> 

I would expect the last betti table to be the same as the second to last one.

Change History (1)

comment:1 Changed 6 years ago by hannes

Owner: changed from somebody to decker
Note: See TracTickets for help on using tickets.