Mermaid
sequenceDiagram
Alice->>+John: Hello John, how are you?
Alice->>+John: John, can you hear me?
Abby-->>+Bob: Hi
John-->>-Alice: Hi Alice, I can hear you!
Abby-->>John: Hi
John-->>-Alice: I feel great!
Bob-->>-Abby: Bye
John-->>Abby: Hi
Abby-->>+Bob: Hi!!
Bob-->>-Abby: Bye, bye