Linear programming using AMPL program

I wrote the code using AMPL program, but it contains errors and tried to correct them, but I do not know how Please can you help me write the correct code

The idea in this code is nested transformation model with converts param supply to var supply

MODEL FILE

# write set

set door; # sources ,,, index i

set class; # destinations ,,, index j

set courses; # subject ,,, index k

set building; # number floor ,,, index b


# write parameter

param capacity {i in door} >= 0;

param demand {j in class} >= 0;

param student {k in courses} >= 0;

param number_floor {b in building} >= 0;

param cost {i in door,b in building} >= 0;

param covid; # The possibility of transmission of covid = 2.4%



# write decision varible

var supply {i in door} >= 0;

var trans_1 {i in door,b in building} >= 0;

var trans_2 {b in building,k in courses} >= 0;

var trans_3 {k in courses,j in class} >= 0;


# write objective function

minimize Total_cost: sum {i in door,b in building} cost[i,b] * supply [i] *covid;


# write constrain

subject to c1.supply_student {i in door} : supply [i] = sum student [k];

subject to c2.supply_capacity {i in door} : supply [i] <= capacity [i];

subject to c3.trans1_supply {i in door} : supply [i] = trans_1 [i,b];

subject to c4.trans2_courses {b in building} : sum {k in courses} courses [b,k] = sum {i in door} trans_2 [i,b];

subject to c5.trans3_student {k in courses} : sum {j in class} trans_3 [k,j] = student [k];

subject to c6.trans3_demand : trans_3 [k,j] <= demand [j];

DATA FILE

# write set with element

set door:= D1 D2 D3 D4; 

set class := A5 A7-9 A11-13 A14-16 A15-17 A19-21
B8-10 B9-11 B12-14 B13-15 B17-19 B18-20
C1 C8 C9 C10 C11 C12 C13 C14 C16 C17 C18 C19 C20;

set courses := Ordinary_Differential_Equations
Complex_analysis Euclidean_and_Non_Euclidean_Geometry;

set building:= first second third;

# write parameter

param number_floor :=
first   1
second  2
third   3;


param covid := 0.024; # The possibility of transmission of covid = 2.4%

param capacity :=
D1   20
D2   13
D3   9
D4   5;

param demand:= 
A5        22
A7-9      30
A11-13    22
A14-16    22
A15-17    22
A18-20    30
A19-21    20
B8-10     30
B9-11     30
B12-14    30
B13-15    30
B17-19    30
B18-20    30
C1        12
C8        12
C9        12
C10       12
C11       12
C12       12
C13       12
C14       12
C16       12
C17       12
C18       12
C19       12
C20       12;

param student:= Ordinary_Differential_Equations 29
Complex_analysis 16 Euclidean_and_Non-Euclidean_Geometry 2;

 
param cost:                               # Time taken to arrive
       first       second       third :=
D1       15           20          25 
D2       22           17          23
D3       19           18          16
D4       12           15          19;

I think the error is in constraint but I don't know