I = io.h
A = zthis.o
B = zthat.o
C = zboth.o
ZZ = zz.o

progboth: $I $C $(ZZ)
	cc -o progboth -DTHIS -DTHAT $C $(ZZ)
	mv progboth whatever

progthis: $I $A $(ZZ)
	cc -o progthis -DTHIS $A $(ZZ)

progthat: $I $B $(ZZ)
	cc -o progthat -DTHAT $B $(ZZ)

$A: $I z.c
	cc -c -o $A -DTHIS z.c

$B: $I z.c
	cc -c -o $B -DTHAT z.c

$C: $I z.c
	cc -c -o $C -DTHIS -DTHAT z.c

$(ZZ): $I zz.c
	cc -c zz.c