 		;;
 		("\\(atan\\|cos\\|exp\\|log\\|s\\(?:in\\|qrt\\)\\)\\([(]\\)" 1 'logtalk-built-in-predicate-face)
 		;;
-		;; term unification:
-		;;
-		("\\\\?=" . 'logtalk-built-in-predicate-face)
-		;;
 		;; stream selection and control:
 		;;
 		("\\(at_end_of_stream\\|c\\(?:lose\\|urrent_\\(?:\\(?:in\\|out\\)put\\)\\)\\|flush_output\\|open\\|s\\(?:et_\\(?:input\\|output\\|stream_position\\)\\|tream_property\\)\\)\\([(]\\)" 1 'logtalk-built-in-predicate-face)

		("\\(arg\\|copy_term\\|functor\\)\\([(]\\)" 1 'logtalk-built-in-predicate-face)
		("=\\.\\." . 'logtalk-built-in-predicate-face)
		;;
		;; arithemtic evaluation:
		;;
		("\\<\\is\\>" . 'logtalk-built-in-predicate-face)

		("\\(atom_\\(?:c\\(?:hars\\|o\\(?:des\\|ncat\\)\\)\\|length\\)\\|char_code\\|number_c\\(?:\\(?:har\\|ode\\)s\\)\\|sub_atom\\)\\([(]\\)" 1 'logtalk-built-in-predicate-face)
		;;
		;; bitwise functors:
		("/\\\\\\|<<\\|>>\\|\\\\/" . 'logtalk-built-in-predicate-face)
		("\\\\" . 'logtalk-built-in-predicate-face)
	))


