# Singular

##### 7.7.7.0. ivSickle
Procedure from library `fpadim.lib` (see fpadim_lib).

Usage:
ivSickle(L,n,[degbound]); L a list of intmats, n an int, degbound an
optional integer

Return:
list, containing intvecs, the mistletoes of A/<L>

Purpose:
Computing the mistletoes for a given Groebner basis L

Assume:
- basering is a Letterplace ring.
- all rows of each intmat correspond to a Letterplace monomial
- if you specify a different degree bound degbound,
degbound <= attrib(basering,uptodeg) holds.

Note:
- If degbound is set, a degree bound will be added. By default there
is no degree bound.
- n is the number of variables.
- If the K-dimension is known to be infinite, a degree bound is needed

Example:
 ```LIB "fpadim.lib"; ring r = 0,(x,y),dp; def R = makeLetterplaceRing(5); // constructs a Letterplace ring setring R; // sets basering to Letterplace ring //some intmats, which contain monomials in intvec representation as rows intmat I1 [2][2] = 1,1,2,2; intmat I2 [1][3] = 1,2,1; intmat J1 [1][2] = 1,1; intmat J2 [2][3] = 2,1,2,1,2,1; print(I1); ==> 1 1 ==> 2 2 print(I2); ==> 1 2 1 print(J1); ==> 1 1 print(J2); ==> 2 1 2 ==> 1 2 1 list G = I1,I2; // ideal, which is already a Groebner basis list I = J1,J2; // ideal, which is already a Groebner basis ivSickle(G,2); // invokes the procedure without any degree bound ==> [1]: ==> 1,2 ==> [2]: ==> 2,1,2 ivSickle(I,2,5); // invokes the procedure with degree bound 5 ==> [1]: ==> 1,2,2,1 ==> [2]: ==> 1,2,2,2,1 ==> [3]: ==> 1,2,2,2,2 ==> [4]: ==> 2,1 ==> [5]: ==> 2,2,1 ==> [6]: ==> 2,2,2,1 ==> [7]: ==> 2,2,2,2,1 ==> [8]: ==> 2,2,2,2,2 ```