In Control flow§

See primary documentation in context for given as a statement

given can follow a statement to set the topic in the statement it follows.

.say given "foo";
# OUTPUT: «foo␤» 
 
printf "%s %02i.%02i.%i",
        <Mo Tu We Th Fr Sa Su>[.day-of-week - 1],
        .day,
        .month,
        .year
    given DateTime.now;
# OUTPUT: «Sa 03.06.2016»