+Convenience syntax for call
+- - - - - - - - - - - - - -
+
+&(thing => $(call thing
+&( thing => $(call thing
+ and specially:
+&(&lc => $(call sub_dir_lc or $(call TOP_lc
+&( &lc => $(call sub_dir_lc or $(call TOP_lc
+ even though lc would normally be thought a filename
+
+Unlike &{...}, this does not involve any dollar-doubling.
+
+Use this when the expansion is going to be a piece of text to be used
+as part of a rule, filename, etc. When the expansion is top-level
+make text (eg, rules), use &:macro and &{...}.
+