Index: generic/predefined.h
===================================================================
diff -u -r5577ecfb071377c5e04f81074e25e2707d2c1400 -r15d57478e3976d747741fd3df9bcb6ecccc7076d
--- generic/predefined.h	(.../predefined.h)	(revision 5577ecfb071377c5e04f81074e25e2707d2c1400)
+++ generic/predefined.h	(.../predefined.h)	(revision 15d57478e3976d747741fd3df9bcb6ecccc7076d)
@@ -2,6 +2,26 @@
 "namespace eval ::nsf {\n"
 "namespace export next current\n"
 "namespace export alias configure finalize interp is my relation\n"
+"proc ::nsf::provide_method {require_name definition {script \"\"}} {\n"
+"set ::nsf::methodIndex($require_name) [list definition $definition script $script]}\n"
+"proc ::nsf::require_method {object name {per_object 0}} {\n"
+"set key ::nsf::methodIndex($name)\n"
+"if {[info exists $key]} {\n"
+"array set \"\" [set $key]\n"
+"if {$(script) ne \"\"} {\n"
+"eval $(script)}\n"
+"if {$per_object} {\n"
+"set cmd [linsert $(definition) 1 -per-object]\n"
+"eval [linsert $cmd 1 $object]} else {\n"
+"eval [linsert $(definition) 1 $object]}} else {\n"
+"error \"cannot require method $name for $object, method unknown\"}}\n"
+"proc ::nsf::mixin {object args} {\n"
+"if {[lindex $args 0] eq \"-per-object\"} {\n"
+"set rel \"object-mixin\"\n"
+"set args [lrange $args 1 end]} else {\n"
+"set rel \"mixin\"}\n"
+"set oldSetting [::nsf::relation $object $rel]\n"
+"uplevel [list ::nsf::relation $object $rel [linsert $oldSetting end $args]]}\n"
 "proc ::nsf::infoError msg {\n"
 "regsub -all \" <object>\" $msg \"\" msg\n"
 "regsub -all \" <class>\" $msg \"\" msg\n"