Implementing Value Subtraction from Tables in GAMS

GAMS
, ,
1

Hello Friends,
If we have the following table in GAMS:

Table X(s, b)
          B1     
0         10 
1         20 
2         30 
3         40;

And another table as follows:

Table Power_Bus(PB, *) 
            P_bus     Q_bus
PB1         0         0
PB2         100       60
PB3         90        40
PB4         120       80
PB5         60        30
PB6         60        20
PB7         200       100
PB8         200       100
PB9         60        20
PB10        60        20;

And we want to write a code that subtracts the values from the first table one by one from a specific value in the second column of the second table, how can we implement this?
I tried to implement it in GAMS but received the following error:

Dimension different - The symbol is referenced with more/less indices as declared

Code:

Sets
    s /0*3/
    b /B1/ 
    PB /PB1*PB10/;

Alias (s,i);

Table X(s,b)
    B1
0   10
1   20
2   30
3   40;

Table Power_Bus(PB,*)
        P_bus   Q_bus
PB1     0       0
PB2     100     60
PB3     90      40
PB4     120     80
PB5     60      30
PB6     60      20
PB7     200     100
PB8     200     100
PB9     60      20
PB10    60      20;

Parameters
    Modified_Power_Bus(PB, *);

Modified_Power_Bus(PB,'P_bus') = Power_Bus(PB,'P_bus');
loop(s,
    Modified_Power_Bus(PB(s),'P_bus') = Power_Bus(PB(s),'P_bus') - X(s,'B1');
);

Display Modified_Power_Bus;

Thank you!