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Vls-filter-datestrs

Filter strings into datestrs and non-datestrs. (See vls-datestr-ps).

Signature
(vls-filter-datestrs x dates others) → (mv dates others)
Arguments: x — Strings to filter.
Guard (string-listp x).; dates — Accumulator for datestrs.
Guard (string-listp dates).; others — Accumulator for non-datestrs.
Guard (string-listp others).
Returns: dates — Type (string-listp dates), given the guard.; others — Type (string-listp others), given the guard.

Definitions and Theorems

Function: vls-filter-datestrs

(defun vls-filter-datestrs (x dates others)
  (declare (xargs :guard (and (string-listp x)
                              (string-listp dates)
                              (string-listp others))))
  (let ((__function__ 'vls-filter-datestrs))
    (declare (ignorable __function__))
    (cond ((atom x) (mv dates others))
          ((vls-datestr-p (car x))
           (vls-filter-datestrs (cdr x)
                                (cons (car x) dates)
                                others))
          (t (vls-filter-datestrs (cdr x)
                                  dates (cons (car x) others))))))

Theorem: string-listp-of-vls-filter-datestrs.dates

(defthm string-listp-of-vls-filter-datestrs.dates
  (implies (and (force (string-listp x))
                (force (string-listp dates))
                (force (string-listp others)))
           (b* (((mv ?dates ?others)
                 (vls-filter-datestrs x dates others)))
             (string-listp dates)))
  :rule-classes :rewrite)

Theorem: string-listp-of-vls-filter-datestrs.others

(defthm string-listp-of-vls-filter-datestrs.others
  (implies (and (force (string-listp x))
                (force (string-listp dates))
                (force (string-listp others)))
           (b* (((mv ?dates ?others)
                 (vls-filter-datestrs x dates others)))
             (string-listp others)))
  :rule-classes :rewrite)