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Svtv-utilities

Svtv->in-width

Given an input name and an SVTV, get the width of the part that is used.

Signature
(svtv->in-width name svtv) → width
Arguments: svtv — Guard (svtv-p svtv).
Returns: width — Type (natp width).

Definitions and Theorems

Function: svtv->in-width

(defun svtv->in-width (name svtv)
  (declare (xargs :guard (svtv-p svtv)))
  (let ((__function__ 'svtv->in-width))
    (declare (ignorable __function__))
    (b* ((look (hons-assoc-equal name (svtv->inmasks svtv)))
         ((unless look)
          (raise "Unknown input: ~x0~%" name)
          0))
      (integer-length (nfix (cdr look))))))

Theorem: natp-of-svtv->in-width

(defthm natp-of-svtv->in-width
  (b* ((width (svtv->in-width name svtv)))
    (natp width))
  :rule-classes :type-prescription)

Theorem: svtv->in-width-of-svtv-fix-svtv

(defthm svtv->in-width-of-svtv-fix-svtv
  (equal (svtv->in-width name (svtv-fix svtv))
         (svtv->in-width name svtv)))

Theorem: svtv->in-width-svtv-equiv-congruence-on-svtv

(defthm svtv->in-width-svtv-equiv-congruence-on-svtv
  (implies (svtv-equiv svtv svtv-equiv)
           (equal (svtv->in-width name svtv)
                  (svtv->in-width name svtv-equiv)))
  :rule-classes :congruence)

Subtopics

Stv->in-width: Same as svtv->in-width.