1S:=simple
 2R=recursive
 3SE:=
 4RE=
 5
 6foo=FOO
 7bar=
 8
 9S+=$(foo) $(bar)
10R+=$(foo) $(bar)
11SE+=$(foo) $(bar)
12RE+=$(foo) $(bar)
13U+=$(foo) $(bar)
14
15bar=BAR
16
17test:
18	echo "$(S)"
19	echo "$(R)"
20	echo "$(SE)"
21	echo "$(RE)"
22	echo "$(U)"
23	echo "$(flavor S)"
24	echo "$(flavor R)"
25	echo "$(flavor SE)"
26	echo "$(flavor RE)"
27	echo "$(flavor U)"