🚀 go-pugleaf

Hello,
This may be a stupid question, but
can someone explain to me why the following  (in an include file)
 #define d define 
 #d NUM   32 
 struct a {  char aa[NUM]; };
leads to the error message:
In file included from test.c:1:
test.h:6: `NUM' undeclared here (not in a function)
whereas
 #define NUM 32
 struct a {  char aa[NUM]; };
compiles with no problems. (using gcc2.4.5 with linux 0.99pl13)
(i got this from a header file which apparently compiled well on a SUN and which uses the first
construct (i.e the #define d define a very large number of times).
Gert van der Zwan