The file Makefile.inc.nw describes the targets that are also used during MAKE
in the subdirectories. In order to generate it from the corresponding .nw file, we have
to give the appropriate target and commands.
359⟨Generate and include Makefile.inc359⟩≡ (346) Makefile.inc: Makefile.inc.nw $(NOTANGLE) -t8 $< > $@ include Makefile.inc UsesNOTANGLE348.