diff -r 92868dab2939 -r 3dd1dcb509ac src/FOLP/Makefile
--- a/src/FOLP/Makefile	Tue Jul 12 18:05:03 1994 +0200
+++ b/src/FOLP/Makefile	Tue Jul 12 18:20:39 1994 +0200
@@ -31,7 +31,8 @@
 			| $(COMP) $(BIN)/Pure;\
 		echo 'open PolyML; use"ROOT";' | $(COMP) $(BIN)/FOLP;;\
 	sml*)	echo 'use"ROOT.ML"; xML"$(BIN)/FOLP" banner;' | $(BIN)/Pure;;\
-	*)	echo Bad value for ISABELLECOMP;;\
+	*)	echo Bad value for ISABELLECOMP: \
+                	$(COMP) is not poly or sml;;\
 	esac
 
 $(BIN)/Pure:
@@ -41,7 +42,8 @@
 	case "$(COMP)" in \
 	poly*)	echo 'use"ex/ROOT.ML"; quit();' | $(COMP) $(BIN)/FOLP ;;\
 	sml*)	echo 'use"ex/ROOT.ML";' | $(BIN)/FOLP;;\
-	*)	echo Bad value for ISABELLECOMP;;\
+	*)	echo Bad value for ISABELLECOMP: \
+                	$(COMP) is not poly or sml;;\
 	esac
 
 .PRECIOUS:   $(BIN)/Pure  $(BIN)/FOLP