added General/history.ML;

--- a/src/Pure/General/ROOT.ML	Tue Jun 16 18:37:11 1998 +0200
+++ b/src/Pure/General/ROOT.ML	Tue Jun 16 18:37:34 1998 +0200
@@ -11,3 +11,4 @@
 use "position.ML";
 use "path.ML";
 use "file.ML";
+use "history.ML";

--- a/src/Pure/IsaMakefile	Tue Jun 16 18:37:11 1998 +0200
+++ b/src/Pure/IsaMakefile	Tue Jun 16 18:37:34 1998 +0200
@@ -23,20 +23,22 @@
 
 Pure: $(OUT)/Pure
 
-$(OUT)/Pure: General/file.ML General/name_space.ML General/object.ML \
-  General/path.ML General/position.ML General/seq.ML General/table.ML \
+$(OUT)/Pure: General/ROOT.ML General/file.ML General/history.ML \
+  General/name_space.ML General/object.ML General/path.ML \
+  General/position.ML General/seq.ML General/table.ML \
   ML-Systems/mlworks.ML ML-Systems/polyml.ML ML-Systems/smlnj-0.93.ML \
   ML-Systems/smlnj.ML ROOT.ML Syntax/ROOT.ML Syntax/ast.ML \
   Syntax/lexicon.ML Syntax/mixfix.ML Syntax/parser.ML Syntax/pretty.ML \
   Syntax/printer.ML Syntax/scan.ML Syntax/source.ML Syntax/symbol.ML \
   Syntax/syn_ext.ML Syntax/syn_trans.ML Syntax/syntax.ML \
   Syntax/token_trans.ML Syntax/type_ext.ML Thy/ROOT.ML \
-  Thy/browser_info.ML Thy/context.ML Thy/thm_database.ML Thy/thy_info.ML \
-  Thy/thy_parse.ML Thy/thy_read.ML Thy/thy_scan.ML Thy/thy_syn.ML \
-  Thy/use.ML attribute.ML axclass.ML basis.ML deriv.ML display.ML \
-  drule.ML envir.ML goals.ML install_pp.ML library.ML logic.ML net.ML \
-  pattern.ML pure_thy.ML search.ML sign.ML sorts.ML tactic.ML tctical.ML \
-  term.ML theory.ML theory_data.ML thm.ML type.ML type_infer.ML unify.ML
+  Thy/browser_info.ML Thy/context.ML Thy/thm_database.ML \
+  Thy/thy_info.ML Thy/thy_parse.ML Thy/thy_read.ML Thy/thy_scan.ML \
+  Thy/thy_syn.ML Thy/use.ML attribute.ML axclass.ML basis.ML deriv.ML \
+  display.ML drule.ML envir.ML goals.ML install_pp.ML library.ML \
+  logic.ML net.ML pattern.ML pure_thy.ML search.ML sign.ML sorts.ML \
+  tactic.ML tctical.ML term.ML theory.ML theory_data.ML thm.ML type.ML \
+  type_infer.ML unify.ML
 	@./mk