-clean:
- $(RM) $(foreach DOC,$(DOCS),\
- $(addprefix $(DOC).,aux log fmt toc bbl blg run.xml out pdf snm nav snm vrb))
+img/%.png: fig/%.dot
+ $(DOT) $(DOTFLAGS) $< > $@
+
+clean: $(DOCS:%=clean-%)
+ $(RM) $(FIGURES)
+
+clean-%:
+ $(RM) $(addprefix $(@:clean-%=%).,acn acr alg aux bbl blg idl idx ilg ind\
+ fmt glg glo gls ist loa lof log lol lot mlog out pdf tdo toc)