etc/options

--- a/etc/options	Sun Apr 09 19:56:52 2017 +0200
+++ b/etc/options	Sun Apr 09 20:17:00 2017 +0200
@@ -82,6 +82,8 @@
 
 section "Detail of Proof Checking"
 
+option record_proofs : int = -1
+  -- "set level of proofterm recording: 0, 1, 2, negative means unchanged"
 option quick_and_dirty : bool = false
   -- "if true then some tools will OMIT some proofs"
 option skip_proofs : bool = false