;--------------------------------------------------------------------------
; File     : PUZ031+1 : TPTP v2.2.0. Released v2.0.0.
; Domain   : Puzzles
; Problem  : Schubert's Steamroller
; Version  : Especial.
; English  : Wolves, foxes, birds, caterpillars, and snails are animals, and
;            there are some of each of them. Also there are some grains, and
;            grains are plants. Every animal either likes to eat all plants
;            or all animals much smaller than itself that like to eat some
;            plants. Caterpillars and snails are much smaller than birds,
;            which are much smaller than foxes, which in turn are much
;            smaller than wolves. Wolves do not like to eat foxes or grains,
;            while birds like to eat caterpillars but not snails.
;            Caterpillars and snails like to eat some plants. Therefore
;            there is an animal that likes to eat a grain eating animal.

; Refs     : [Pel86] Pelletier (1986), Seventy-five Problems for Testing Au
;          : [Hah94] Haehnle (1994), Email to G. Sutcliffe
; Source   : [Hah94]
; Names    : Pelletier 47 [Pel86]

; Status   : theorem
; Rating   : 0.00 v2.1.0
; Syntax   : Number of formulae    :   21 (   6 unit)
;            Number of atoms       :   55 (   0 equality)
;            Maximal formula depth :    9 (   3 average)
;            Number of connectives :   36 (   2 ~  ;   4  |;  14  &)
;                                         (   0 <=>;  16 =>;   0 <=)
;                                         (   0 <~>;   0 ~|;   0 ~&)
;            Number of predicates  :   10 (   0 propositional; 1-2 arity)
;            Number of functors    :    0 (   0 constant; --- arity)
;            Number of variables   :   33 (   0 singleton;  22 !;  11 ?)
;            Maximal term depth    :    1 (   1 average)

; Comments : This problem is named after Len Schubert.
;          : tptp2X -f kif PUZ031+1.p 
;--------------------------------------------------------------------------
; pel47_1_1, axiom.
    (forall (?A)
      (=> (wolf ?A)
          (animal ?A) ) )

; pel47_1_2, axiom.
    (exists (?A)(wolf ?A) )

; pel47_2_1, axiom.
    (forall (?A)
      (=> (fox ?A)
          (animal ?A) ) )

; pel47_2_2, axiom.
    (exists (?A)(fox ?A) )

; pel47_3_1, axiom.
    (forall (?A)
      (=> (bird ?A)
          (animal ?A) ) )

; pel47_3_2, axiom.
    (exists (?A)(bird ?A) )

; pel47_4_1, axiom.
    (forall (?A)
      (=> (caterpillar ?A)
          (animal ?A) ) )

; pel47_4_2, axiom.
    (exists (?A)(caterpillar ?A) )

; pel47_5_1, axiom.
    (forall (?A)
      (=> (snail ?A)
          (animal ?A) ) )

; pel47_5_2, axiom.
    (exists (?A)(snail ?A) )

; pel47_6_1, axiom.
    (exists (?A)(grain ?A) )

; pel47_6_2, axiom.
    (forall (?A)
      (=> (grain ?A)
          (plant ?A) ) )

; pel47_7, axiom.
    (forall (?A)
      (=> (animal ?A)
          (or (forall (?B)
                (=> (plant ?B)
                    (eats ?A ?B) ) )
              (forall (?C)
                (=> (and (and (animal ?C)
                            (much_smaller ?C ?A) )
                        (exists (?D)
                          (and (plant ?D)
                              (eats ?C ?D) ) ) )
                    (eats ?A ?C) ) ) ) ) )

; pel47_8, axiom.
    (forall (?A ?B)
      (=> (and (bird ?B)
              (or (snail ?A)
                  (caterpillar ?A) ) )
          (much_smaller ?A ?B) ) )

; pel47_9, axiom.
    (forall (?A ?B)
      (=> (and (bird ?A)
              (fox ?B) )
          (much_smaller ?A ?B) ) )

; pel47_10, axiom.
    (forall (?A ?B)
      (=> (and (fox ?A)
              (wolf ?B) )
          (much_smaller ?A ?B) ) )

; pel47_11, axiom.
    (forall (?A ?B)
      (=> (and (wolf ?A)
              (or (fox ?B)
                  (grain ?B) ) )
          (not (eats ?A ?B) ) ) )

; pel47_12, axiom.
    (forall (?A ?B)
      (=> (and (bird ?A)
              (caterpillar ?B) )
          (eats ?A ?B) ) )

; pel47_13, axiom.
    (forall (?A ?B)
      (=> (and (bird ?A)
              (snail ?B) )
          (not (eats ?A ?B) ) ) )

; pel47_14, axiom.
    (forall (?A)
      (=> (or (caterpillar ?A)
              (snail ?A) )
          (exists (?B)
            (and (plant ?B)
                (eats ?A ?B) ) ) ) )

; pel47, conjecture.
    (not (exists (?A ?B)
          (and (and (animal ?A)
                  (animal ?B) )
              (exists (?C)
                (and (and (grain ?C)
                        (eats ?B ?C) )
                    (eats ?A ?B) ) ) ) ) )

;--------------------------------------------------------------------------