(define impc:ti:allocate-var?
  (lambda (ast)
    (cond ((null? ast) #f)
          ((member ast *impc:lambdaslist*) #t)
          ((pair? ast)
           (or (impc:ti:allocate-var? (car ast))
               (impc:ti:allocate-var? (cdr ast))))
          (else #f))))