measured-subset

(in-package "ACL2")

(define measured-subset
  ((fn symbolp) (wrld plist-worldp))
  :returns (measured-subset "A @(tsee symbol-listp).")
  :verify-guards nil
  :parents (std/system/function-queries)
  :short "Subset of the formal arguments
          of a named logic-mode recursive function
          that occur in its @(see measure) expression."
  :long (topstring-p "See @(tsee measured-subset+) for an enhanced variant of this utility.")
  (b* ((justification (getpropc fn 'justification nil wrld)))
    (access justification justification :subset)))