Question: How do i perform optimization on a function that contains integrals?

I am trying to call an optimization function for a set of operations where the object function contains integrals. i get this error when i try to do the optimization, i actually want to optimize a cost function, this is the error i get: Error, (in Optimization:-NLPSolve) integration range or variable must be specified in the second argument, got 1. = 4 .. 7

here is my work: 

a2 := 18;
b2 := 5;
a1 := 3;
b1 := 2.5;
ci := 0.05;
cr := 1;
cf := 10;
p := 0.1;
L := 0.5;
S := 3;
T := 10;
cud := 50;
co := 0.02;
tr := 0.006;
ti := 0.0014;
tf := 0.014;
K := 2;
A := 2;
M := 7;
f01 := x -> b1*(x/a1)^(b1 - 1)*exp(-(x/a1)^b1)/a1;
f02 := x -> b2*(x/a2)^(b2 - 1)*exp(-(x/a2)^b2)/a2;
fx := x -> p*f01(x) + (1 - p)*f02(x);
fh := h -> L*exp(-L*h);
Fh := h -> 1 - exp(-L*h);

P1_1 := (K, A, M) -> sum(int(fx(x)*(1 - Fh(i*A - x)), x = (i - 1)*A .. i*A), i = 1 .. K);
L1_1 := (K, A, M) -> sum((i*A + tr + i*ti)*P1_1(K, A, M), i = 1 .. K);
C1_1 := (K, A, M) -> sum((ci*i + cr)*P1_1(K, A, M), i = 1 .. K);
NULL;
P2_1 := (K, A, M) -> sum(int(fh(h)*fx(x), [h = 0 .. i*A - x, x = (i - 1)*A .. i*A]), i = 1 .. K);
L2_1 := (K, A, M) -> sum((tf + (i - 1)*ti)*int((x + h)*fh(h)*fx(x), [h = 0 .. i*A - x, x = (i - 1)*A .. i*A]), i = 1 .. K);
C2_1 := (K, A, M) -> sum(((i - 1)*ci + cf)*P2_1(K, A, M), i = 1 .. K);
P3_1 := (K, A, M) -> int(fh(h)*fx(x), [h = 0 .. M - x, x = A*K .. M]);
L3_1 := (K, A, M) -> (K*ti + tf)*int((x + h)*fh(h)*fx(x), [h = 0 .. M - x, x = A*K .. M]);
C3_1 := (K, A, M) -> (K*ci + cf)*P3_1(K, A, M);
P4_1 := (K, A, M) -> int(fx(x)*(1 - Fh(M - x)), x = A*K .. M);
L4_1 := (K, A, M) -> (K*ti + tr + M)*int(fx(x)*(1 - Fh(M - x)), x = A*K .. M);
C4_1 := (K, A, M) -> (K*ci + cr)*int(fx(x)*(1 - Fh(M - x)), x = A*K .. M);
P5_1 := (K, A, M) -> int(fx(x), x = M .. infinity);
L5_1 := (K, A, M) -> (K*ti + tr + M)*int(fx(x), x = M .. infinity);
C5_1 := (K, A, M) -> (K*ci + cr)*int(fx(x), x = M .. infinity);
Ptotal_1 := (K, A, M) -> P1_1(K, A, M) + P2_1(K, A, M) + P3_1(K, A, M) + P4_1(K, A, M) + P5_1(K, A, M);
Ptotal_1(K, A, M);
evalf(Ptotal_1(K, A, M));
Ltotal_1 := (K, A, M) -> L1_1(K, A, M) + L2_1(K, A, M) + L3_1(K, A, M) + L4_1(K, A, M) + L5_1(K, A, M);
evalf(Ltotal_1(K, A, M));
Ctotal_1 := (K, A, M) -> C1_1(K, A, M) + C2_1(K, A, M) + C3_1(K, A, M) + C4_1(K, A, M) + C5_1(K, A, M);
Cost_rate_1 := (K, A, M) -> Ctotal_1(K, A, M)/Ltotal_1(K, A, M);
integralOF := int(Cost_rate_1(K, A, M), x = 1 .. 2);
evalf(integralOF);
                          0.2759938793

MTBOF := Ltotal_1(K, A, M)/(P2_1(K, A, M) + P3_1(K, A, M));
evalf(MTBOF);
                          159.4642167

rd := 1/MTBOF;
ro := 1/M + rd;
const1 := 0 <= K;
const2 := K*A <= M;
const3 := M <= 20;
const4 := 0 <= A;
const5 := 0 <= M;
totalconstr := {const1, const2, const3, const4, const5};

optimized_cost := Optimization:-Minimize(integralOF, totalconstr);
Error, (in Optimization:-NLPSolve) integration range or variable must be specified in the second argument, got 1. = 4 .. 7
NULL;
 

please, i need assitance urgently.. thanks