Relative simple layout, but right arrow not working

Question

Hello,

how can I  solve the relative simple layout problem?
I want to have a left to right arrow from "b" to "c".

@startuml
rectangle a as a
rectangle S1 as S1 {
  rectangle b as b
}
rectangle c as c
rectangle d as d

a -D-> b : down
b -D-> d : down
c -D-> d : down

' should go right not left
b -R-> c : should be right
@enduml

Thank you and best regards
Helmut

Comments

Well I found a way, but it makes no sense!

b -[norank]d-> c : should go down

---

Hello K. & M.,

For that, another solution is to use `together` (for b & c),  as:

@startuml
rectangle a as a
together {
rectangle S1 as S1 {
  rectangle b as b
}
rectangle c as c
}
rectangle d as d

a -D-> b : down
b -D-> d : down
c -D-> d : down

' should go right not left
b -R-> c : should be right
@enduml

If that can help,
Regards,
Th.

---

Thank you, I think together is the more generic and logical solution
Helmut