SimpleReservation.tla

-------------------------- MODULE DullReservation --------------------------
EXTENDS Naturals, FiniteSets

VARIABLE reservations

Coaches == { "A", "B" }
SeatNumbers == 1..10
Seats == Coaches \X SeatNumbers

70PercentTrainOccupation == (70 * Cardinality(Seats)) \div 100

----

Reserve(seatCount) ==
    /\ Cardinality(UNION reservations) + seatCount <= 70PercentTrainOccupation
    /\ \E seats \in SUBSET Seats:
        /\ Cardinality(seats) = seatCount
        /\ reservations' = reservations \union {seats}

----

Init == reservations = {}
Next == \E seatCount \in 1..Cardinality(Seats): Reserve(seatCount)

----

TypeCheck == reservations \in SUBSET SUBSET Seats

AtMost70PercentTrainOccupation == Cardinality(UNION reservations) <= 70PercentTrainOccupation 

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