compose(f,g)={
  x -> f(g(x))
};

fcf()={
  my(A,B);
  A=[x->sin(x), x->cos(x), x->x^2];
  B=[x->asin(x), x->acos(x), x->sqrt(x)];
  for(i=1,#A,
    print(compose(A[i],B[i])(.5))
  )
};