+# Cannot express dependencies directly on file names because of Automake.
+# Obfuscate with a variable.
+doc_bison = doc/bison
+$(doc_bison).dvi: $(FIGS_GV:.gv=.eps)
+$(doc_bison).info: $(FIGS_GV:.gv=.txt)
+$(doc_bison).pdf: $(FIGS_GV:.gv=.pdf)
+$(doc_bison).html: $(FIGS_GV:.gv=.png)
+
+TEXI2DVI = texi2dvi --build-dir=doc/bison.t2d -I doc