addMarked_addtermsMarked_sqrsfirstrecipMarked_termsdblMarked_firstsqrMarked_dbl0nilconsYXNterms(N)cons(recip(sqr(N)))sqr(0)0sqr(s)sdbl(0)0dbl(s)sadd(0,X)Xadd(s,Y)sfirst(0,X)nilfirst(s,cons(Y))cons(Y)terms(N)cons(recip(sqr(N)))sqr(0)0sqr(s)sdbl(0)0dbl(s)sadd(0,X)Xadd(s,Y)sfirst(0,X)nilfirst(s,cons(Y))cons(Y)Marked_terms(N)Marked_sqr(N)