-LABLGTK_DIR = /usr/lib/ocaml/lablgtk
-LABLGTK_MATHVIEW_DIR = /usr/lib/ocaml/lablgtk/mathview
-MINIDOM_DIR = /usr/lib/ocaml/minidom
-PXP_DIR = /usr/lib/ocaml/site-lib/pxp
-NETSTRING_DIR = /usr/lib/ocaml/site-lib/netstring
+OCAML_ROOT = /usr/lib/ocaml
+LABLGTK_DIR = $(OCAML_ROOT)/lablgtk
+LABLGTK_MATHVIEW_DIR = $(OCAML_ROOT)/lablgtk/mathview
+MINIDOM_DIR = $(OCAML_ROOT)/minidom
+PXP_DIR = $(OCAML_ROOT)/site-lib/pxp
+NETSTRING_DIR = $(OCAML_ROOT)/site-lib/netstring
OCAMLC = ocamlc -I $(LABLGTK_DIR) -I $(LABLGTK_MATHVIEW_DIR) -I $(PXP_DIR) -I $(NETSTRING_DIR) -I $(MINIDOM_DIR) -I mlmathview
OCAMLOPT = ocamlopt -I $(LABLGTK_DIR) -I $(LABLGTK_MATHVIEW_DIR) -I mlgtk_devel -I $(PXP_DIR) -I $(NETSTRING_DIR) -I $(MINIDOM_DIR) -I mlmathview
OCAMLDEP = ocamldep