      subroutine ext1f(n,a,b,c)
c     (very) simple example 1
c     -->link('ext1f.o','ext1f');
c     -->a=[1,2,3];b=[4,5,6];n=3;
c     -->c=call('ext1f',n,1,'i',a,2,'d',b,3,'d','out',[1,3],4,'d')
c     c=a+b
c     Copyright Inria/Enpc
      double precision a(*),b(*),c(*)
      do 1 k=1,n
         c(k)=a(k)+b(k)
 1    continue
      return
      end
