I am trying to run a code. But the error message read thus:
“Error 71: The symbol shown has been declared as an equation, but no
symbolic equation (…) was found. hint  look for commas in the
documentation text for the equations. use quotes around the Text or
eliminate the commas”
I have done all I felt is required, but I am still having the error.
Please can someone someone have a solution to this error?
My code is below:
\
 ILLUSTRATIVE EXAMPLE:
Sets
i existing facility /FA, FB/
s new siting facility /NA, NB, CR /
r toxic relaese type /1 /
ri(i,r) set of releases in existing facilities /FA.1/
k slice angle /136/
u facilities interconnected/FA,FB,NA, NB,CR/
n(i,r,k) set of release type r from exisiting facility i in direction
k /FA.1.136/
Alias (u,j);
Set
M(u,j) a set whose elements indicate which paired facilities
are interconnected
/FA. NA, NA.NB/;
Parameters Lx(i) Length of existing facilities
/FA 20
FB 15 /
Parameter Lsx(s) Length of new facilities
/NA 10
NB 30
CR 15 /
Parameter Ly(i) Depth of existing facilities
/FA 10
FB 15 /
Parameter Lsy(s) Depth Lys of new facilities
/NA 30
NB 15
CR 15 /
Parameter x(i) xcoordinates of the center points for existing
facility
/FA 15
FB 12.5/
Parameter y(i) ycoordinates of the center points for existing
facility
/FA 10
FB 27.5/
\
 FA and FB are already existing facilities and NA1,NB and the control
room CR  are desired to be sited in the land; where FA can have “chlorine
release” from  it centre point (15,10).
parameter aa(k) for the exponential decay model al is in degrees
/1 0.029197
2 0.033666
3 0.043151
4 0.058328
5 0.036068
6 0.060453
7 0.10547
8 0.16368
9 0.2646
10 0.39906
11 0.50906
12 0.54443
13 0.49927
14 0.37822
15 0.28116
16 0.195
17 0.14738
18 0.12714
19 0.11643
20 0.1094
21 0.12335
22 0.13943
23 0.15254
24 0.15506
25 0.1529
26 0.14245
27 0.12469
28 0.11427
29 0.091316
30 0.068746
31 0.053675
32 0.040917
33 0.02948
34 0.02277
35 0.01954
36 0.022943/
parameter bb(k) for the exponential decay model al is in degrees
/1 0.020654
2 0.019243
3 0.019414
4 0.021643
5 1.0077
6 0.31112
7 0.080694
8 0.033326
9 0.022263
10 0.018084
11 0.016308
12 0.016263
13 0.016065
14 0.014920
15 0.015945
16 0.014816
17 0.011996
18 0.012345
19 0.012345
20 0.015803
21 0.014073
22 0.01159
23 0.011456
24 0.012738
25 0.013635
26 0.011556
27 0.010012
28 0.011646
29 0.012353
30 0.010601
31 0.0095219
32 0.0097168
33 0.0098091
34 0.0095465
35 0.0097283
36 0.015462 /;
Scalar Cp cost of a pipe per meter of length in USD /196.8/ ;
Scalar Cl cost per meter of land in USD /6/ ;
Scalar Cpp compensation cost to pay per fatality in USD /
10000000/ ;
Scalar Ax Length of occupied land in xdirection in meters /
500/ ;
Scalar Ay Length of occupied land in ydirection in meters /
250/ ;
Scalar st street size in meters /5/ ;
Scalar Nint slice interval /36/ ;
Scalar tl expected life time of the plant in years /45/ ;
Scalar t exposure time to toxic gas in minutes /10/ ;
Scalar f frequency of release per year /0.00058/ ;
Scalar Ps the expected population in facility s /10/ ;
Variables
Cland “Cost of occupied land”
cpiping “piping cost”
Crisk “cost of risk”
Dminx "minimum separation in xdirection between facilities "
Dminy “minimum separation in ydirection between facilities "
ma(k) “an nslice vector where each element represents the slope
evaluated in each alpha slice angle”
al(k) “valid slice”
Svx(i) vconvinient slice vector to define quardrant position”
Svy(i) “convinient slice vector to define quardrant position”
xs(s) “xcoordinate of a new facility”
ys(s) "ycoordinate of a new facility "
yy(j) “ycoordinate”
xu(j) “xcoordinate”
yu(j) “ycoordinate”
z "hhh "
Positive variables
xA(s,i) “xcoordinate if facility s is sited in position A wrt
facility i”
xLL(s,i) “xcoordinate if facility s is sited in position L wrt
facility i”
xR(s,i) “xcoordinate if facility s is sited in position R wrt
facility i”
xAD(s,i) “xcoordinate if facility s is sited between position A
& D wrt facility i”
yA(s,i) “ycoordinate if facility s is sited in position A wrt
facility i”
yD(s,i) “xcoordinate if facility s is sited in position D wrt
facility i”
yLR(s,i) “xcoordinate if facility s is sited between position
L& R wrt facility i”
x1(i,s,k) “xposition of facility s wrt i in the the slice
direction k”
y1(i,s,k) “yposition of facility s wrt i in the the slice
direction k”
d(s,i) “Euclidian separation distance between both facilities
(i.e i and s)”
dd(u,j) “the separation distance between two facilities”
Binary Variable
BL(s,i) “1 if s is positioned to the left of i and 0 if otherwise”
BR(s,i) “1 if s is positioned to the right of i and 0 if otherwise”
BAD(s,i) “1 if s is positioned in between A and D of and 0 if
otherwise”
BA(s,i) “1 if s is positioned to the above of i and 0 if otherwise”
BD(s,i) “1 if s is positioned to the below of i and 0 if otherwise”
B(i,s,k) “1 indicate the slice direction of the position of facility
s wrt the releasing facility i” ;
Equations
Obj “objective function”

Pipe Connectivity
distconstraint1(u,j) “distance constraint 1”
distconstraint2(s,i) “distance constraint 2” 
Land Constraints:
landconstraint1(s) “Land constraint 1”
landconstraint2(s,i) “Land constraint 2”
landconstraint3(s) “Land constraint 3”
landconstraint4(s,i) “Land constraint 4”
 Nonoverlapping Constraints:
Nonovalap1(s,i) “nonoverlapping constraint1”
Nonovalap2(s,i) “nonoverlapping constraint2”
Nonovalap3(s,i) “nonoverlapping constraint3”
Nonovalap4(s,i) “nonoverlapping constraint4”
Nonovalap5(s,i) “nonoverlapping constraint5”
Nonovalap6(s,i) “nonoverlapping constraint6”
Nonovalap7(s,i) “nonoverlapping constraint7”
Nonovalap8(s,i) “nonoverlapping constraint8”
Nonovalap9(s,i) "nonoverlapping constraint9 "
Nonovalap10(s,i) "nonoverlapping constraint10 "
Nonovalap11(s,i) “nonoverlapping constraint11”
Nonovalap12(s,i) “nonoverlapping constraint12”
Nonovalap13(s,i) “nonoverlapping constraint13”
Nonovalap14(s,i) “nonoverlapping constraint14”
Nonovalap15(s,i) “nonoverlapping constraint15”
Nonovalap16(s,i) "nonoverlapping constraint16 "
Nonovalap17(s,i) “nonoverlapping constraint17”
 Toxic Release Constraints:
Toxic1(i,s) “toxic release constraint1”
Toxic2(i,s) “toxic release constraint2”
Toxic3(i,s,k) "toxic release constraint3 "
Toxic4(i,s,k) “toxic release constraint4”
Toxic5(i,s,k) “toxic release constraint5”
Toxic6(i,s,k) “toxic release constraint6”
Toxic7(i,s) “toxic release constraint7”
Toxic8(i,s,k) “toxic release constraint8”
Toxic9(i,s,k) “toxic release constraint9”
Toxic10(k) “toxic release constraint10” ;
 Objective function( minimizing the sume of the cost of land, pinping
and financial risk)
Obj… z =e= ClAxAy + sum((u,j) ,Cpdd(u,j)) +
sum((i,s,k) ,B(i,s,k) aa(k)*exp((bb(k)*d(s,i))));
 Pipe Connectivity constraint
distconstraint1(u,j)$M(u,j)… dd(u,j)**2 =e= (xu(u)  xu(j))**2
 (yu(u)  yy(j))**2 ;
distconstraint2(s,i)… d(s,i)**2 =e= (x(i)  xs(s))**2 + (y(i) 
ys(s))**2 ;

Land Constraints:

landconstraint1(s,i).. (Lx(s)/2 + st) =l= x(s) =l= Lx(i) 
(Lx(s)/2 + st) ;
landconstraint1(s)… (Lsx(s)/2 + st) =l= xs(s) ;
landconstraint2(s,i)… xs(s) =l= Lx(i)  (Lsx(s)/2 + st) ;
landconstraint3(s)… (Lsy(s)/2 + st) =l= ys(s) ;
landconstraint4(s,i)… ys(s) =l= Ly(i)  (Lsy(s)/2 + st) ;
\
 Nonoverlapping Constraints:
Nonovalap1(s,i)(ord(s) gt ord(i)).. xs(s) =e= xLL(s,i) + xR(s,i) +
xAD(s,i) ;
Nonovalap2(s,i)(ord(s) gt ord(i))… ys(s) =e= yA(s,i) + yD(s,i) +
yLR(s,i) ;
Nonovalap3(s,i)(ord(s) gt ord(i)).. xLL(s,i) =l= (x(i) 
Dminx(s,i))*BL(s,i);
Nonovalap4(s,i)(ord(s) gt ord(i))… xR(s,i) =g= (x(i) +
Dminx(s,i))*BR(s,i) ;
Nonovalap5(s,i)(ord(s) gt ord(i)).. xAD(s,i) =g= (x(i) 
Dminx(s,i))*BAD(s,i) ;
Nonovalap6(s,i)(ord(s) gt ord(i))… xAD(s,i) =l= (x(i) +
Dminx(s,i))*BAD(s,i) ;
Nonovalap7(s,i)(ord(s) gt ord(i)).. yA(s,i) =g= (y(i) 
Dminy(s,i))*BA(s,i) ;
Nonovalap8(s,i)(ord(s) gt ord(i))… yD(s,i) =l= (y(i) 
Dminy(s,i))*BD(s,i) ;
Nonovalap9(s,i)$(ord(s) gt ord(i))… BL(s,i) + BR(s,i) + BAD(s,i)
=e= 1 ;
Nonovalap10(s,i)(ord(s) gt ord(i)).. xLL(s,i) =l= ((Lx(i)stLsx(s))/
2)*BL(s,i) ;
Nonovalap11(s,i)(ord(s) gt ord(i))… xR(s,i) =l= ((Lx(i)stLsx(s))/
2)*BR(s,i) ;
Nonovalap12(s,i)(ord(s) gt ord(i)).. xAD(s,i)=l= ((Lx(i)stLsx(s))/
2)*BAD(s,i);
Nonovalap13(s,i)(ord(s) gt ord(i))… xA(s,i) =l= ((Ly(i)stLsy(s))/
2)BA(s,i);
Nonovalap14(s,i)(ord(s) gt ord(i)).. xLL(s,i) =l= ((Ly(i)stLsy(s))/
2)*BD(s,i) ;
Nonovalap15(s,i)(ord(s) gt ord(i))… xLL(s,i) =l= ((Ly(i)stLsy(s))/
2)(1BAD(s,i));
Nonovalap16(s,i)$(ord(s) gt ord(i))… Dminx(s,i)=e=(Lsx(s) + Lx(i))/2
 st ;
Nonovalap17(s,i)$(ord(s) gt ord(i))… Dminy(s,i)=e=(Lsy(s) + Ly(i))/2  st ;
Nonovalap18(s,i)$k…d(i,s) =l= 100B(i,s,k)
 Toxic Release Constraints:
Toxic1(i,s)… xs(s) =e= sum(k, x1(i,s,k));
Toxic2(i,s)… ys(s) =e= sum(k, y1(i,s,k));
Toxic3(i,s,k)… Svy(i)*(y1(i,s,k)B(i,s,k)y(i)) =g= 0 ;
Toxic4(i,s,k)… Svx(i)(x1(i,s,k)B(i,s,k)*x(i)) =g= 0 ;

Toxic5(i,s,k)$ ri(i,r).. Svy(i)*(y(i,s,k)B(i,s,k)*y(i)) =l=
Svx(i)ma(k)(x(i,s,k)B(i,s,k)*x(i));

Toxic6(i,s,k)$ ri(i,r).. Svx(k)*(x(i,s,k)B(i,s,k)*x(i)) =g=
Svx(k)ma(k)(x(i,s,k)B(i,s,k)*x(i));
Toxic7(i,s)… sum(k,B(i,s,k)) =e= 1 ;
Toxic8(i,s,k)… x1(i,s,k)=l= B(i,s,k)(Lx(i)  st  Lsx(s)/
2);
Toxic9(i,s,k)… y1(i,s,k)=l= B(i,s,k)(Ly(i)  st  Lsy(s)/
2);
Toxic10(k) … ma(k) =e= tan((2al(k) 180)/Nint) ;
Model layout/All/;
option limrow = 1000 ;
option limcol = 1000;

option optcr=0.001;
Solve layout using minlp minimizing z ;
\