src/CTT/Makefile

 	@if [ -d $${ISABELLEBIN:?}/Pure ];\
 		then echo Bad value for ISABELLEBIN: \
 			$(BIN) is the Isabelle source directory; \
 			exit 1; \
 	fi
-	@case `expr "//$(COMP)" : '[^ ]*/\(.*\)'` in \
+	@case `basename "$(COMP)"` in \
 	poly*)	echo 'make_database"$(BIN)/CTT"; quit();'  \
 			| $(COMP) $(BIN)/Pure;\
 		if [ "$${MAKE_HTML}" = "true" ]; \
 		then echo 'open PolyML; make_html := true; exit_use_dir".";' \
 		       | $(COMP) $(BIN)/CTT;\

 
 $(BIN)/Pure:
 	cd ../Pure;  $(MAKE)
 
 test:	ex/ROOT.ML $(BIN)/CTT  $(EX_FILES) 
-	@case `expr "//$(COMP)" : '[^ ]*/\(.*\)'` in \
+	@case `basename "$(COMP)"` in \
 	poly*)	echo 'exit_use"ex/ROOT.ML"; quit();' | $(COMP) $(BIN)/CTT ;;\
 	sml*)	echo 'exit_use"ex/ROOT.ML";' | $(BIN)/CTT;;\
 	*)	echo Bad value for ISABELLECOMP: \
 			\"$(COMP)\" is not poly or sml;;\
 	esac