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Vl-weirdint-p

Vl-bit-p

Representation of a single Verilog bit (0, 1, X, or Z).

Verilog has four register-transfer level values, 0, 1, X, and Z. We represent these values using the keyword symbols accepted by vl-bit-p:

:vl-0val means 0,
:vl-1val means 1,
:vl-xval means X, and
:vl-zval means Z.

This is an ordinary defenum.

Function: vl-bit-p

(defun vl-bit-p (x)
  (declare (xargs :guard t))
  (or (eq x ':vl-0val)
      (eq x ':vl-1val)
      (eq x ':vl-xval)
      (eq x ':vl-zval)))

Theorem: type-when-vl-bit-p

(defthm type-when-vl-bit-p
  (implies (vl-bit-p x)
           (if (symbolp x)
               (if (not (equal x 't))
                   (not (equal x 'nil))
                 'nil)
             'nil))
  :rule-classes :compound-recognizer)

Subtopics

Vl-bit->char: Get the character for a vl-bit-p.