OBJ = main.o input.o factorial.o output.o
SOURCE = main.c input.c factorial.c output.c
CC  = gcc
testfac:      ${OBJ}
              ${CC} -o $@ ${OBJ}

main.o:       myinclude.h

input.o:      myinclude.h

factorial.o:  myinclude.h

output.o:     myinclude.h

clean:
              -rm -f *.o testfac core 
all:
              gcc -c ${SOURCE}
              gcc -o testfac ${OBJ}