D.5.5.8 displayInvariants

Procedure from library hnoether.lib (see hnoether_lib).

Usage:

displayInvariants(INPUT); INPUT list or poly

Assume:

INPUT is a bivariate polynomial, or the output of develop(f), or of extdevelop(develop(f),n), or (one entry of) the list hne in the ring created by hnexpansion(f[,"ess"]).

Return:

none

Display:

invariants of the corresponding branch, resp. of all branches, in a better readable form.

Note:

In case the Hamburger-Noether expansion of the curve f is needed for other purposes as well it is better to calculate this first with the aid of hnexpansion and use it as input instead of the polynomial itself.

Example:

LIB "hnoether.lib";
ring exring=0,(x,y),dp;
list hne=develop(y4+2x3y2+x6+x5y);
displayInvariants(hne);
→  characteristic exponents  : 4,6,7
→  generators of semigroup   : 4,6,13
→  Puiseux pairs             : (3,2)(7,2)
→  degree of the conductor   : 16
→  delta invariant           : 8
→  sequence of multiplicities: 4,2,2,1,1

See also: develop; hnexpansion; intersection; invariants.