slightly more standard data merge: Symtax.merge (K true) avoids equality on abstract type Pretty.T and gracefully accepts overriding, Symtab.join prefers first entry as usual;
## targets
default: LNCS
## global settings
SRC = $(ISABELLE_HOME)/src
OUT = $(ISABELLE_OUTPUT)
LOG = $(OUT)/log
USEDIR = $(ISABELLE_TOOL) usedir -i true -d ps -D document -v true
## LNCS
LNCS: $(LOG)/HOL-LNCS.gz
$(LOG)/HOL-LNCS.gz: LNCS/ROOT.ML LNCS/document/root.tex LNCS/document/root.bib LNCS/*.thy
@$(USEDIR) HOL LNCS
## clean
clean:
@rm -f $(LOG)/HOL-LNCS.gz