=== modified file 'common.zsh'
--- common.zsh	2017-12-13 01:49:47 +0000
+++ common.zsh	2017-12-13 01:39:29 +0000
@@ -35,7 +35,6 @@
 # Logical variable handling
 ground() {
 	(($# == 1)) || die "usage: $0 <variable>"
-	(($+vars[$1])) || die "$0: undefined variable: ${(qqq)1}"
 	(($+vals[$vars[$1]]))
 }