Subject: Branching in sequence diagrams

> How do we show branching (if... then... else)
> relationships in the sequence diagrams? (i.e. If I
> wanted to say if condition is true then send value A
> else send value B.) Drawing two arrows one after
> another on a sequence diagram only shows sequential
> execution right? Is there an example of branching in
> the book?

One can simply use several sequence diagrams to show the various cases.  One
can also show conditions in brackets before a message.  This is how it is done
in the solution.  There is a way to show the messages actually splitting, but
my CASE tool (Rational Rose) does not support this.