type-inferrer (cons head tail result)
  (define! result &pair -inf.0 +inf.0))
(define-type-inferrer (box val result)
  (define! result &box -inf.0 +inf.0))
;; No inferrers for pair or box accessors; because type checks dominate
;; these accessors, they would add no information.

(define-type-inferrer/param (allocate-struct param vtable result)
  (define nfields param)
  ;; It would be nice to be able to restrict the vtable-size of vtable,
  ;; but because vtables are themselves structs which have associated
  ;; size ranges, there's nowhere to put the vtable-size ranges.  Humm!
  (define! result &struct nfields nfields))
(define-type-inferrer (vtable-size vtable result)
  (define! result &u64 0 (target-max-size-t/scm)))
;; No predicate inferrers for vtable-has-unboxed-fields? and
;; vtable-field-boxed?, as there is nowhere to store this info.
(define-type-inferrer (struct-vtable struct result)
  (define! result &struct 0 (target-max-size-t/scm)))
(define-type-inferrer/param (struct-ref param struct result)
  (define idx param)
  (restrict! struct &struct (1+ idx) (target-max-size-t/scm))
  (define! result &all-types -inf.0 +inf.0))
(define-type-inferrer/param (struct-set! param struct val)
  (define idx param)
  (restrict! struct &struct (1+ idx) (target-max-size-t/scm)))

(define-type-inferrer (bv-contents bv result)
  (define! result &other-heap-object -inf.0 +inf.0))
(define-type-inferrer (bv-length bv result)
  (define! result &u64 (&min/0 bv) (&max/size bv)))

(define-type-inferrer (string-length str result)
  (define! result &u64 (&min/0 str) (&max/size str)))
(define-type-inferrer (string-ref str idx result)
  (define! result &u64 0 *max-codepoint*))

(define-type-inferrer (symbol-hash sym result)
  (define! result &u64 0 &u64-max))

(define-type-inferrer/param (make-closure param code result)
  (define nfree param)
  (define! result &procedure nfree nfree))
;; No information would be provided by closure-ref / closure-set!
;; inferrers.