diff --git a/lib/ulib/base.array b/lib/ulib/base.array
index 5dadff4..3940090 100644
--- a/lib/ulib/base.array
+++ b/lib/ulib/base.array
@@ -3,10 +3,3 @@
 ##@cooked nocomments
 uprovide base.array
 urequire base.core
-
-function is_array() {
-# tester si la variable $1 est un tableau
-    local -a arrays
-    eval "arrays=($(declare -p -a | while read dummy dummy var; do echo ${var%%=*}; done))"
-    array_contains arrays "$1"
-}
diff --git a/lib/ulib/base.core b/lib/ulib/base.core
index 9a540f5..d3c4484 100644
--- a/lib/ulib/base.core
+++ b/lib/ulib/base.core
@@ -377,6 +377,16 @@ function err2out() {
     "$@" 2>&1
 }
 
+function is_defined() {
+# tester si la variable $1 est définie
+    [ -n "$(declare -p "$1" 2>/dev/null)" ]
+}
+function is_array() {
+# tester si la variable $1 est un tableau
+    case "$(declare -p "$1" 2>/dev/null)" in declare\ -a*) return 0;; esac
+    return 1
+}
+
 # cf http://www.fvue.nl/wiki/Bash:_Passing_variables_by_reference
 function upvar() {
 # Assign variable one scope above the caller