TRACE ALL
 /* TRY A Then do */
 
 if '1' then if '0' then say 11
                    else say 10
        else if '1' then say 01
                    else say 00
 
say '-------------------------------------'
  if '1';
   else do;
 
say select..
select
  when '0'; say 0 1
  when '0'; say 0 2
  when '0'; say 0 3
 
  when '1'; do; say 1 4
            say line 2
            select;
              when 'l'; hi;
              otherwise say 'bb'
    say'dd'
              end;
 
 
            say line 3
            say line 4; end
 
  when rubbish
 
end
 
 say dun
    end
 
 say i 'd' say 1
say say then say hi
 'b' SAY dun 2