<<
begin {
  print "In the beginning:"
}
end {
  print "At the end:"
}
# Populates the main block
print "In ...";
print "... the middle!"
>>

begin { print "HELLO" }
begin { print "WORLD" }
end   { print "GOODBYE" }
end   { print "WORLD" }

# Immediately executed
print "HOW ARE THINGS?"
# Also immediately executed
<
x=1;
y=2;
print x+y;
>

:blocks

:begin
:main
:end