class - Create a design pattern for objects in two categories, both covering all objects -

i design class diagram following problem:

from 1 perspective in domain, elements ("elements") either input elements or output elements, not both.

from perspective, either nodes or arrows (but not both).

for example, element e1 can have 1 of following situations:

1) input node

2) output node

3) input arrow

4) output arrow.

i encode without using constraint (like ocl)

so far, i've come following design diagram (grey classes abstract): enter image description here

my question: there more efficient pattern fit problem more accurately, without multi-inheritance?

with requirements , per understanding, i'd rather use strategy pattern instead of inheritance. 2 different behaviors

and element contain functions related 2 behaviors (as has both of these). diagram (the element referring ishapebehavior , iinputoutputbehavior)

enter image description here

Lix