Sum up an array of variables in a constraint:
MaxCap := sum(p in 1..10) buy(p) <= 100
MaxCap := sum(p in 1..10) (buy(p) + sum(r in 1..5) make(p,r)) <= 100
MaxCap := sum(p in 1..NP, t in 1..NT)
CAP(p)*buy(p,t) <= MAXCAP
MaxCap := sum(p in 1..NP) (2*CAP(p)*buy(p)/10 +
SCAP(p)*sell(p)) <= MAXCAP
Use a loop to assign an array of constraints:
forall(t in 2..NT)
Inven(t) := bal(t) = bal(t-1) + buy(t) - sell(t)
Use
do/
end-do to group several statements into one loop
forall(t in 1..NT) do
MaxRef(t) := sum(i in 1..NI) use(i,t) <= MAXREF(t)
Inven(t) := store(t) = store(t-1) + buy(t) - use(t)
end-do
Can nest
forall statements:
forall(t in 1..NT) do
MaxRef(t) := sum(i in 1..NI) use(i,t) <= MAXREF(t)
forall(i in 1..NI)
Inven(i,t) := store(i,t) = store(i,t-1) + buy(i,t) - use(i,t)
end-do Similarly for specification of bounds (a bound is just a simple unnamed constraint):
forall(i in 1..NI) do
forall(t in 1..NT) store(i,t) <= MAXSTORE(t)
store(i,0) = STORE0
end-do
May include
conditions in sums or loops:
forall(c in 1..10 | CAP(c)>=100.0)
MaxCap(c) :=
sum(i in 1..10, j in 1..10 | i<>j)
TECH(i,j,c)*x(i,j,c) <= MAXTECH(c)
