esrd_rootsa.html

FUNCTION: esrd_rootsa - positive roots of the Tits-form

CALLING SEQUENCE:
esrd_rootsa(o,n)
esrd_rootsa(o,n,smin)
esrd_rootsa(o,n,smin,smax)

PARAMETERS:
o - the orbit type of an exceptional sincere representation directed algebra
n - a positive integer less than or equal to esrd_num(o)
smin, smax - optional parameters evaluating to a name

SYNOPSIS:

esrd_rootsa(o,n) returns for the class n of exceptional sincere representation directed algebras belonging to orbit type o a list of all positive roots of the corresponding Tits-form.

Via the optional third parameter smin the unique minimal sincere positive root of the Tits-form may be obtained.

Via the optional forth parameter smax a list of all maximal positive roots may be obtained.

See esrd_orbittypes for valid values of o.

EXAMPLES:

> esrd_rootsa(221,3,'smin','smax');

> print(smin);

> print(smax);

SEE ALSO: esrd_rootss

BACK TO: start page of the crep online manual, esrd