Edge: call:answer() -> var(out) # var:out
Edge: func() { str("the answer is 42") } -> call:answer() # call:answer
Edge: str("the answer is 42") -> func() { str("the answer is 42") } # body
Vertex: call:answer()
Vertex: func() { str("the answer is 42") }
Vertex: str("the answer is 42")
Vertex: var(out)