deleting multiple intermediate files

[Vance Shipley]

I have a target which relies on two intermediate files. Only one of
these gets deleted afterwards.  How can I get the other deleted?

Makefile:

%.a %.b:        %.foo
        cp $< $*.a
        cp $< $*.b

%.bar:  %.a %.b
        cat $^ > $@


Here is what I get when I try to make the target:

$ make test.bar
cp test.foo test.a
cp test.foo test.b
cat test.a test.b > test.bar
rm test.a

I tried adding ".INTERMEDIATE:  %.a %.b" but that had no effect.

        -Vance