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;;----General SUMO background
(subclass TransitiveRelation Relation)
(subclass SymmetricRelation Relation)
(subclass BinaryRelation Relation)
(subclass TernaryRelation Relation)

(<=> (instance ?REL TransitiveRelation)
     (forall (?INST1 ?INST2 ?INST3)
        (=> (and (?REL ?INST1 ?INST2) (?REL ?INST2 ?INST3))
            (?REL ?INST1 ?INST3))))

(<=> (instance ?REL SymmetricRelation)
     (forall (?INST1 ?INST2)
        (=> (?REL ?INST1 ?INST2) (?REL ?INST2 ?INST1))))

(=> (and (subclass ?X ?Y) (subclass ?Y ?Z))
    (subclass ?X ?Z))

(=> (and (instance ?X ?Y) (subclass ?Y ?Z))
    (instance ?X ?Z))

;;----Every 3-dimensional volume has a numeric surface area.
(instance surfaceArea BinaryRelation)
(domain surfaceArea 1 SelfConnectedObject)
(domain surfaceArea 2 AreaMeasure)
(=> (surfaceArea ?S ?M)
    (exists (?O) (surface ?S ?O)))

(=> (surfaceArea ?S (MeasureFn ?N ?U))
    (measure ?S (MeasureFn  ?N ?U)))

;;----Every 3-dimensional volume has a numeric surface to volume ratio.
(instance surfaceToVolumeRatio BinaryRelation)
(domain surfaceToVolumeRatio 1 SelfConnectedObject)
(domain surfaceToVolumeRatio 2 FunctionQuantity)
(=> (surfaceToVolumeRatio ?O (PerFn (MeasureFn ?A ?U) (MeasureFn ?B ?U)))
    (and
      (surfaceArea ?O (MeasureFn ?N (SquareFn ?U2)))
      (measure ?O (MeasureFn ?N2 (CubeFn ?U2)))
      (equal
        (PerFn (MeasureFn ?A ?U) (MeasureFn ?B ?U))
        (PerFn (MeasureFn ?N (SquareFn ?U2)) (MeasureFn ?N2 (CubeFn ?U2))))))

;;----Every cell and environment have a numeric exchange rate between the
;;----cell and the environment.
(instance exchangeRate TernaryRelation)
(domain exchangeRate 1 Cell)
(domain exchangeRate 2 Region)
(domain exchangeRate 3 FunctionQuantity)
(=> (exchangeRate ?C ?R (PerFn (MeasureFn ?N ?U) (MeasureFn ?N2 ?TU)))
    (instance ?TU TimeDuration))

(=> (and
      (exchangeRate ?C ?R (PerFn (MeasureFn ?N ?U) (MeasureFn ?N2 ?TU)))
      (greaterThan ?N 0))
    (exists (?M ?S)
      (and
        (instance ?S Substance)
        (measure ?S (MeasureFn ?N ?U))
        (instance ?M Motion)
        (duration (WhenFn ?M) (MeasureFn ?N2 ?TU))
        (holdsDuring (ImmediatePastFn ?M) (orientation ?S ?C Inside))
        (holdsDuring (ImmediateFutureFn ?M) (orientation ?S ?C Outside)))))

(=> (and
      (exchangeRate ?C ?R (PerFn (MeasureFn ?N ?U) (MeasureFn ?N2 ?TU)))
      (greaterThan 0 ?N))
    (exists (?M ?S)
      (and
        (instance ?S Substance)
        (measure ?S (MeasureFn ?N ?U))
        (instance ?M Motion)
        (duration (WhenFn ?M) (MeasureFn ?N2 ?TU))
        (holdsDuring (ImmediatePastFn ?M) (orientation ?S ?C Outside))
        (holdsDuring (ImmediateFutureFn ?M) (orientation ?S ?C Inside)))))

;;----Every cell has an environment.
(instance cellEnvironmentFn UnaryFunction)
(domain cellEnvironmentFn 1 Cell)
(range cellEnvironmentFn Region)
(=> (cellEnvironmentFn ?C ?R)
    (orientation ?C ?R Inside))

;;----Proportional is symmetric and transitive
(instance proportional SymmetricRelation)
(instance proportional TransitiveRelation)
(domain proportional 1 Relation)
(domain proportional 2 Relation)

(=> (proportional ?X ?Y)
    (proportional ?Y ?X))

(=> (and (proportional ?X ?Y) (proportional ?Y ?Z))
    (proportional ?X ?Z))

;;----A high surface to volume ratio facilitates the exchange of materials
;;----between a cell and its environment.
(proportional surfaceToVolumeRatio exchangeRate)

;;----Surface area is proportional to surface to volume ratio.
(proportional surfaceArea surfaceToVolumeRatio)

;;----If something numeric is important, and is proportional to another
;;----numeric thing, then the other numeric thing is important.
(instance Important RelationalAttribute)
(=> (and
      (instance ?R Relation)
      (attribute ?R Important)
      (proportional ?R ?R2))
    (attribute ?R2 Important))

;;----The exchange rate of a cell with its environment is important.
(attribute exchangeRate Important)

;;----Why is surface area important to normal cell function?
(attribute surfaceArea Important)

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