    (herald "Otway-Rees Protocol"
      (comment "Standard version using variables of sort mesg"))
    (comment "CPSA 3.6.2")
    (comment "All input read from or.scm")

Tree 0.

    (defprotocol or basic
      (defrole init
        (vars (a b s name) (na text) (k skey) (m text))
        (trace (send (cat m a b (enc na m a b (ltk a s))))
          (recv (cat m (enc na k (ltk a s))))))
      (defrole resp
        (vars (a b s name) (nb text) (k skey) (m text) (x y mesg))
        (trace (recv (cat m a b x))
          (send (cat m a b x (enc nb m a b (ltk b s))))
          (recv (cat m y (enc nb k (ltk b s)))) (send y)))
      (defrole serv
        (vars (a b s name) (na nb text) (k skey) (m text))
        (trace
          (recv
            (cat m a b (enc na m a b (ltk a s)) (enc nb m a b (ltk b s))))
          (send (cat m (enc na k (ltk a s)) (enc nb k (ltk b s)))))
        (uniq-orig k)))

Item 0, Children: 1 2.

    (defskeleton or
      (vars (x y mesg) (nb m text) (s a b name) (k skey))
      (defstrand resp 4 (x x) (y y) (nb nb) (m m) (a a) (b b) (s s) (k k))
      (non-orig (ltk a s) (ltk b s))
      (uniq-orig nb)
      (label 0)
      (unrealized (0 2))
      (origs (nb (0 1)))
      (comment "2 in cohort - 2 not yet seen"))

Item 1, Parent: 0, Child: 3.

    (defskeleton or
      (vars (x y mesg) (nb m na m-0 text) (s a b a-0 name) (k skey))
      (defstrand resp 4 (x x) (y y) (nb nb) (m m) (a a) (b b) (s s) (k k))
      (defstrand serv 2 (na na) (nb nb) (m m-0) (a a-0) (b b) (s s) (k k))
      (precedes ((0 1) (1 0)) ((1 1) (0 2)))
      (non-orig (ltk a s) (ltk b s))
      (uniq-orig nb k)
      (operation encryption-test (added-strand serv 2) (enc nb k (ltk b s))
        (0 2))
      (label 1)
      (parent 0)
      (unrealized (1 0))
      (comment "1 in cohort - 1 not yet seen"))

Item 2, Parent: 0, Child: 4.

    (defskeleton or
      (vars (x y mesg) (nb m nb-0 m-0 text) (s a b b-0 name) (k skey))
      (defstrand resp 4 (x x) (y y) (nb nb) (m m) (a a) (b b) (s s) (k k))
      (defstrand serv 2 (na nb) (nb nb-0) (m m-0) (a b) (b b-0) (s s) (k k))
      (precedes ((0 1) (1 0)) ((1 1) (0 2)))
      (non-orig (ltk a s) (ltk b s))
      (uniq-orig nb k)
      (operation encryption-test (added-strand serv 2) (enc nb k (ltk b s))
        (0 2))
      (label 2)
      (parent 0)
      (unrealized (1 0))
      (comment "1 in cohort - 1 not yet seen"))

Item 3, Parent: 1, Children: 5 6 7.

    (defskeleton or
      (vars (x y mesg) (nb m na text) (s a b name) (k skey))
      (defstrand resp 4 (x x) (y y) (nb nb) (m m) (a a) (b b) (s s) (k k))
      (defstrand serv 2 (na na) (nb nb) (m m) (a a) (b b) (s s) (k k))
      (precedes ((0 1) (1 0)) ((1 1) (0 2)))
      (non-orig (ltk a s) (ltk b s))
      (uniq-orig nb k)
      (operation encryption-test (displaced 2 0 resp 2)
        (enc nb m-0 a-0 b (ltk b s)) (1 0))
      (label 3)
      (parent 1)
      (unrealized (1 0))
      (comment "3 in cohort - 3 not yet seen"))

Item 4, Parent: 2, Children: 8 9, Seen Child: 6.

    (defskeleton or
      (vars (x y mesg) (nb m nb-0 text) (s a name) (k skey))
      (defstrand resp 4 (x x) (y y) (nb nb) (m m) (a a) (b a) (s s) (k k))
      (defstrand serv 2 (na nb) (nb nb-0) (m m) (a a) (b a) (s s) (k k))
      (precedes ((0 1) (1 0)) ((1 1) (0 2)))
      (non-orig (ltk a s))
      (uniq-orig nb k)
      (operation encryption-test (displaced 2 0 resp 2)
        (enc nb m-0 b b (ltk b s)) (1 0))
      (label 4)
      (parent 2)
      (seen 6)
      (unrealized (1 0))
      (comment "3 in cohort - 2 not yet seen"))

Item 5, Parent: 3.

    (defskeleton or
      (vars (x y mesg) (nb m na text) (s a b name) (k skey))
      (defstrand resp 4 (x x) (y y) (nb nb) (m m) (a a) (b b) (s s) (k k))
      (defstrand serv 2 (na na) (nb nb) (m m) (a a) (b b) (s s) (k k))
      (defstrand init 1 (na na) (m m) (a a) (b b) (s s))
      (precedes ((0 1) (1 0)) ((1 1) (0 2)) ((2 0) (1 0)))
      (non-orig (ltk a s) (ltk b s))
      (uniq-orig nb k)
      (operation encryption-test (added-strand init 1)
        (enc na m a b (ltk a s)) (1 0))
      (label 5)
      (parent 3)
      (unrealized)
      (shape)
      (maps ((0) ((nb nb) (s s) (a a) (b b) (k k) (m m) (x x) (y y))))
      (origs (k (1 1)) (nb (0 1))))

Item 6, Parent: 3.

    (defskeleton or
      (vars (x y mesg) (nb m text) (s a name) (k skey))
      (defstrand resp 4 (x x) (y y) (nb nb) (m m) (a a) (b a) (s s) (k k))
      (defstrand serv 2 (na nb) (nb nb) (m m) (a a) (b a) (s s) (k k))
      (precedes ((0 1) (1 0)) ((1 1) (0 2)))
      (non-orig (ltk a s))
      (uniq-orig nb k)
      (operation encryption-test (displaced 2 0 resp 2)
        (enc na m a a (ltk a s)) (1 0))
      (label 6)
      (parent 3)
      (unrealized)
      (shape)
      (maps ((0) ((nb nb) (s s) (a a) (b a) (k k) (m m) (x x) (y y))))
      (origs (k (1 1)) (nb (0 1))))

Item 7, Parent: 3.

    (defskeleton or
      (vars (x y x-0 mesg) (nb m na text) (s a name) (k skey))
      (defstrand resp 4 (x x) (y y) (nb nb) (m m) (a a) (b a) (s s) (k k))
      (defstrand serv 2 (na na) (nb nb) (m m) (a a) (b a) (s s) (k k))
      (defstrand resp 2 (x x-0) (nb na) (m m) (a a) (b a) (s s))
      (precedes ((0 1) (1 0)) ((1 1) (0 2)) ((2 1) (1 0)))
      (non-orig (ltk a s))
      (uniq-orig nb k)
      (operation encryption-test (added-strand resp 2)
        (enc na m a a (ltk a s)) (1 0))
      (label 7)
      (parent 3)
      (unrealized)
      (shape)
      (maps ((0) ((nb nb) (s s) (a a) (b a) (k k) (m m) (x x) (y y))))
      (origs (k (1 1)) (nb (0 1))))

Item 8, Parent: 4.

    (defskeleton or
      (vars (x y mesg) (nb m nb-0 text) (s a name) (k skey))
      (defstrand resp 4 (x x) (y y) (nb nb) (m m) (a a) (b a) (s s) (k k))
      (defstrand serv 2 (na nb) (nb nb-0) (m m) (a a) (b a) (s s) (k k))
      (defstrand init 1 (na nb-0) (m m) (a a) (b a) (s s))
      (precedes ((0 1) (1 0)) ((1 1) (0 2)) ((2 0) (1 0)))
      (non-orig (ltk a s))
      (uniq-orig nb k)
      (operation encryption-test (added-strand init 1)
        (enc nb-0 m a a (ltk a s)) (1 0))
      (label 8)
      (parent 4)
      (unrealized)
      (shape)
      (maps ((0) ((nb nb) (s s) (a a) (b a) (k k) (m m) (x x) (y y))))
      (origs (k (1 1)) (nb (0 1))))

Item 9, Parent: 4.

    (defskeleton or
      (vars (x y x-0 mesg) (nb m nb-0 text) (s a name) (k skey))
      (defstrand resp 4 (x x) (y y) (nb nb) (m m) (a a) (b a) (s s) (k k))
      (defstrand serv 2 (na nb) (nb nb-0) (m m) (a a) (b a) (s s) (k k))
      (defstrand resp 2 (x x-0) (nb nb-0) (m m) (a a) (b a) (s s))
      (precedes ((0 1) (1 0)) ((1 1) (0 2)) ((2 1) (1 0)))
      (non-orig (ltk a s))
      (uniq-orig nb k)
      (operation encryption-test (added-strand resp 2)
        (enc nb-0 m a a (ltk a s)) (1 0))
      (label 9)
      (parent 4)
      (unrealized)
      (shape)
      (maps ((0) ((nb nb) (s s) (a a) (b a) (k k) (m m) (x x) (y y))))
      (origs (k (1 1)) (nb (0 1))))