This command take a poset P and returns a new poset that contains all elements in P that are not in L. The relations on the remaining elements are all relations that held in P.
Alternately, if a boolean function is given as input instead of a list, all elements for which the function returns true are removed from P.
i1 : S = QQ[a,b]; |
i2 : P = divisorPoset(a*b^2); |
i3 : P.GroundSet 2 2 o3 = {1, b, b , a, a*b, a*b } o3 : List |
i4 : Q = dropElements(P, {a,a*b^2}) o4 = Poset{cache => CacheTable{} } 2 GroundSet => {1, b, b , a*b} RelationMatrix => | 1 1 1 1 | | 0 1 1 1 | | 0 0 1 0 | | 0 0 0 1 | 2 2 2 2 Relations => {(1, 1), (1, b), (1, b ), (1, a*b), (b, b), (b, b ), (b, a*b), (b , b ), (a*b, a*b)} o4 : Poset |
i5 : R = dropElements(P, m -> first degree m === 2) o5 = Poset{cache => CacheTable{} } 2 GroundSet => {1, b, a, a*b } RelationMatrix => | 1 1 1 1 | | 0 1 0 1 | | 0 0 1 1 | | 0 0 0 1 | 2 2 2 2 2 Relations => {(1, 1), (1, b), (1, a), (1, a*b ), (b, b), (b, a*b ), (a, a), (a, a*b ), (a*b , a*b )} o5 : Poset |