Implement strip
diff --git a/test/strip.mk b/test/strip.mk
new file mode 100644
index 0000000..61bea5f
--- /dev/null
+++ b/test/strip.mk
@@ -0,0 +1,14 @@
+XY:=x 	y
+X:=$(subst y, ,$(XY))
+Y:=$(subst x, ,$(XY))
+
+test:
+	echo $(X)
+	echo $(Y)
+	echo $(strip $(X))
+	echo $(strip $(Y))
+	echo $(strip $(Y),$(X))
+
+# TODO: Hard to tell why. Fix this.
+#test2:
+#	echo $(strip $(X),$(Y))