+# This allows -j make option while making sure only one lilypond-book instance
+# is running at the same time
+define CHAIN_RULE
+$(i)
+$(i):
+endef
+
+$(eval $(firstword $(MASTER_TEXI_FILES)): $(foreach i, $(wordlist 2, $(words $(MASTER_TEXI_FILES)), $(MASTER_TEXI_FILES)),$(CHAIN_RULE)))