Description
the function
tSpreadIdeal(I,t) gives the ideal generated by all the
tspread monomials which are among the generators of the ideal
I.
This function calls the method
tSpreadList(l,t) to sieve the
tspread monomials from the list
l, of the generators of the ideal
I.
Let $u=x_{i_1}x_{i_2}\cdots x_{i_d}$ a monomial of $S=K[x_1,\ldots,x_n]$, with $1\le i_1\le i_2\le\dots\le i_d\le n$. The monomial
u is called $t$spread if $i_{j+1}i_j\ge t$ for all $j\in [d1]$. A monomial ideal is called
tspread if it is generated by
tspread monomials.
Examples:
i1 : S=QQ[x_1..x_14]
o1 = S
o1 : PolynomialRing

i2 : I=ideal {x_3*x_7*x_10*x_14, x_1*x_5*x_9*x_13}
o2 = ideal (x x x x , x x x x )
3 7 10 14 1 5 9 13
o2 : Ideal of S

i3 : tSpreadIdeal(I,3)
o3 = ideal (x x x x , x x x x )
3 7 10 14 1 5 9 13
o3 : Ideal of S

i4 : tSpreadIdeal(I,4)
o4 = ideal(x x x x )
1 5 9 13
o4 : Ideal of S
