Is it legal a sequence diagram without lifeline?

2
votes

i've my project and this is my Sequence Diagram. Is it legal? enter image description here

Can i start my sequence diagram like that?

1
umlsequence-diagramvisual-paradigm

1 Answers

3
votes

The first message on the left is a found message (see §17.4.4.1 page 577 of formal/2017-12-05) and its use is perfectly legal.