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Vl-evatom-plain-p

We say a vl-evatom-p is plain when it has no posedge or negedge, and the expression is a simple identifier. For instance, an event control list like @(a or b or c) contains only plain evatoms.

Signature
(vl-evatom-plain-p x) → plainp
Arguments: x — Guard (vl-evatom-p x).

Typically an always block that has this sort of event control contains either behavioral-style combinational logic or latches, whereas an event control with something like @(posedge clk) expresses flip-flops.

Definitions and Theorems

Function: vl-evatom-plain-p

(defun vl-evatom-plain-p (x)
  (declare (xargs :guard (vl-evatom-p x)))
  (let ((__function__ 'vl-evatom-plain-p))
    (declare (ignorable __function__))
    (b* (((vl-evatom x) x))
      (and (eq x.type :vl-noedge)
           (vl-idexpr-p x.expr)))))

Theorem: vl-evatom->type-when-vl-evatom-plain-p

(defthm vl-evatom->type-when-vl-evatom-plain-p
  (implies (vl-evatom-plain-p x)
           (equal (vl-evatom->type x) :vl-noedge)))

Theorem: vl-idexpr-p-of-vl-evatom->expr-when-vl-evatom-plain-p

(defthm vl-idexpr-p-of-vl-evatom->expr-when-vl-evatom-plain-p
  (implies (vl-evatom-plain-p x)
           (vl-idexpr-p (vl-evatom->expr x))))

Theorem: vl-evatom-plain-p-of-vl-evatom-fix-x

(defthm vl-evatom-plain-p-of-vl-evatom-fix-x
  (equal (vl-evatom-plain-p (vl-evatom-fix x))
         (vl-evatom-plain-p x)))

Theorem: vl-evatom-plain-p-vl-evatom-equiv-congruence-on-x

(defthm vl-evatom-plain-p-vl-evatom-equiv-congruence-on-x
  (implies (vl-evatom-equiv x x-equiv)
           (equal (vl-evatom-plain-p x)
                  (vl-evatom-plain-p x-equiv)))
  :rule-classes :congruence)