diff --git a/prolog.jsf b/prolog.jsf
index 0364e8d..f072399 100644
--- a/prolog.jsf
+++ b/prolog.jsf
@@ -19,7 +19,11 @@
 	"0-9"		first_digit	recolor=-1
 	"'"		string_sq_1	recolor=-1
 	"\""		string_dq_1	recolor=-1
-	"a-z"		atom		buffer
+
+	# marking -> predicate hilite
+	# buffering -> keyword hilite
+	"a-z"		atom		mark buffer
+
 	"A-Z"		variable	recolor=-1
 	"_"		_variable
 	"[]"		brace		recolor=-1
@@ -94,7 +98,7 @@
 
 # list of keywords includes some predicates...
 :atom Idle
-	*		idle		noeat strings
+	*		atom_end	noeat markend strings
 	"append"	kw
 	"atom"		kw
 	"atomic"	kw
@@ -127,6 +131,19 @@ done
 :kw Keyword
 	*		idle		noeat
 
+:atom_end Idle
+	*		idle		noeat
+	" "		atom_end
+	"("		pred_end	recolormark
+	":"		maybe_pred_end
+
+:pred_end Bad
+	*		idle		noeat
+
+:maybe_pred_end Idle
+	*		idle		noeat
+	"-"		pred_end	recolormark
+
 :variable Variable
 	*		idle		noeat
 	"a-zA-Z0-9_"	variable