src/Pure/ROOT.ML

 use "pattern.ML";
 use "unify.ML";
 use "theory.ML";
 use "interpretation.ML";
 use "proofterm.ML";
+use "deriv.ML";
 use "thm.ML";
 use "more_thm.ML";
 use "facts.ML";
 use "pure_thy.ML";
 use "display.ML";