Unable to coerce dictionary to morphism between finite posets

[Jennifer O'Brien]

Using the code below, I am unsure why I cannot form the identity map (or others such as constant maps) via dictionary. I have done the same process for finite simplicial complexes, so maybe this isn't implemented for posets? Thanks for any help.

The input:

X=Poset({1:[],2:[1]})
Hom(X,X)({1:1,2:2})

The output error message:

TypeError: Unable to coerce x (={1: 1, 2: 2}) to a morphism in Set of Morphisms from Finite poset containing 2 elements to Finite poset containing 2 elements in Join of Category of finite posets and Category of finite enumerated sets and Category of facade sets

[Nils Bruin]

On Saturday, July 9, 2016 at 2:12:35 AM UTC-7, Jennifer O'Brien wrote:

Using the code below, I am unsure why I cannot form the identity map (or others such as constant maps) via dictionary. I have done the same process for finite simplicial complexes, so maybe this isn't implemented for posets? Thanks for any help.

The input:

X=Poset({1:[],2:[1]})
Hom(X,X)({1:1,2:2})

There's a generic solution:

sage: D={1:1,2:2}
sage: Hom(X,X)(lambda x: D[x])
Generic endomorphism of Finite poset containing 2 elements