X-Git-Url: https://git.distorted.org.uk/~mdw/sod/blobdiff_plain/71ecc48e20c8651175b16f37ee66ca08a36cc1c6..a07d8d005f69c0f9f5da2e09c6ee39cb1e1801aa:/pset.lisp?ds=sidebyside

diff --git a/pset.lisp b/pset.lisp
index 9db8c4f..a9bbde9 100644
--- a/pset.lisp
+++ b/pset.lisp
@@ -269,7 +269,8 @@
 		(unless (p-seenp prop)
 		  (cerror*-with-location (p-location prop)
 					 "Unknown property `~A'"
-					 (p-name prop))))
+					 (p-name prop))
+		  (setf (p-seenp prop) t)))
 	      pset)))
 
 ;;;--------------------------------------------------------------------------